黄团队

Cite this: Chem. Sci., 2021, 12, 14432
引用此文：Chem.科学，2021，12，14432
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Received 28th July 2021 2021 年 7 月 28 日收到
Accepted 9th October 2021
2021 年 10 月 9 日接受
DOI: 10.1039/d1sc04138j DOI：10.1039/d1sc04138j
rsc.li/chemical-science

Plasticizer and catalyst co-functionalized PEDOT:PSS enables stretchable electrochemical sensing of living cells $†$
增塑剂和催化剂共官能化 PEDOT:PSS 可实现活细胞的可拉伸电化学传感 $†$

Jing Yan, $^{a}$ Yu Qin, $^{a}$ Wen-Ting Fan, $^{a}$ Wen-Tao Wu, $^{a}$ Song-Wei Lv, $^{b}$ Li-Ping Yan, $^{a}$ Yan-Ling Liu (D) $^{* a}$ and Wei-Hua Huang (1) $^{a}$
Jing Yan、 $^{a}$ Yu Qin、 $^{a}$ Wen-Ting Fan、 $^{a}$ Wen-Tao Wu、 $^{a}$ Song-Wei Lv、 $^{b}$ Li-Ping Yan、 $^{a}$ Yan-Ling Liu (D) $^{* a}$ 和 Wei-Hua Huang (1) $^{a}$

Abstract 摘要

Recently, stretchable electrochemical sensors have stood out as a powerful tool for the detection of soft cells and tissues, since they could perfectly comply with the deformation of living organisms and synchronously monitor mechanically evoked biomolecule release. However, existing strategies for the fabrication of stretchable electrochemical sensors still face with huge challenges due to scarce electrode materials, demanding processing techniques and great complexity in further functionalization. Herein, we report a novel and facile strategy for one-step preparation of stretchable electrochemical biosensors by doping ionic liquid and catalyst into a conductive polymer (poly(3,4ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS). Bis(trifluoromethane) sulfonimide lithium salt as a small-molecule plasticizer can significantly improve the stretchability and conductivity of the PEDOT:PSS film, and cobalt phthalocyanine as an electrocatalyst endows the film with excellent electrochemical sensing performance. Moreover, the functionalized PEDOT:PSS retained good cell biocompatibility with two extra dopants. These satisfactory properties allowed the real-time monitoring of stretch-induced transient hydrogen peroxide release from cells. This work presents a versatile strategy to fabricate conductive polymer-based stretchable electrodes with easy processing and excellent performance, which benefits the in-depth exploration of sophisticated life activities by electrochemical sensing.
最近，可拉伸电化学传感器已成为检测软细胞和组织的有力工具，因为它们可以完美地适应生物体的变形，并同步监测机械诱发的生物分子释放。然而，由于电极材料稀缺、加工技术要求高以及进一步功能化的复杂性，现有的可拉伸电化学传感器制造策略仍面临巨大挑战。在此，我们报告了一种新颖而简便的策略，即在导电聚合物（聚（3,4-亚乙二氧基噻吩）：聚（苯乙烯磺酸），PEDOT：PSS）中掺杂离子液体和催化剂，从而一步制备可拉伸的电化学生物传感器。双（三氟甲烷）磺酰亚胺锂盐作为小分子增塑剂可显著改善 PEDOT:PSS 薄膜的拉伸性和导电性，而酞菁钴作为电催化剂则赋予了薄膜优异的电化学传感性能。此外，添加了两种掺杂剂的功能化 PEDOT:PSS 还具有良好的细胞生物相容性。这些令人满意的特性允许对拉伸诱导的细胞瞬时过氧化氢释放进行实时监测。这项工作提出了一种制造基于导电聚合物的可拉伸电极的多功能策略，它易于加工且性能卓越，有利于通过电化学传感深入探索复杂的生命活动。

Introduction 导言

Cells in the body are constantly exposed to mechanical forces and could perceive and transduce them into biochemical signals.

^{1 - 6}

Currently, cell mechanotransduction has gained tremendous attention due to the crucial role of mechanical forces in cell function, and the accurate characterization of the ensuing biochemical signals during the mechanotransduction process is vitally important for understanding cellular mechanical signalling.

^{2 - 5}

Since cell mechanotransduction involves rapid mechanochemical conversion (within a second),

^{3}

soft stretchable electrochemical sensors with a fast response and high sensitivity have emerged as a powerful technique to induce the mechanical deformation of cells and simultaneously monitor the transient biochemical response in real time.

^{7 - 11}

Recently, stretchable electrochemical sensors have made significant progress in exploring dynamic mechanotransduction, and mechanically evoked molecules (e.g.
人体内的细胞不断受到机械力的作用，它们可以感知机械力并将其转化为生化信号。

^{1 - 6}

目前，由于机械力在细胞功能中的关键作用，细胞机械传导受到了极大的关注，而准确描述机械传导过程中随之产生的生化信号对于理解细胞机械信号至关重要。

^{2 - 5}

由于细胞的机械传导涉及快速的机械化学转换（一秒钟内），

^{3}

具有快速响应和高灵敏度的软拉伸电化学传感器已成为诱导细胞机械变形并同时实时监测瞬时生化响应的强大技术。

^{7 - 11}

近来，可拉伸电化学传感器在探索动态机械传导方面取得了重大进展，机械诱发的分子（如钙离子、镁离子、钾离子、镁离子等）也在研究中得到了应用。

hydrogen peroxide

(H_{2} O_{2})

, nitric oxide (NO) and serotonin) release from stretched endothelial cells and inflated intestine were successfully monitored.

^{9, 12 - 15}

This notable advance is of great benefit to study the mechanism of force-activated signalling in mechanotransduction.

(H_{2} O_{2})

过氧化氢、一氧化氮（NO）和血清素）的释放。

^{9, 12 - 15}

这一显著进步对研究机械传导中力激活信号的机制大有裨益。

As for the fabrication of stretchable electrodes, most of the reported sensors were based on well-designed zero- or onedimensional nanomaterials. Zero-dimensional nanomaterials with high density, such as agglomerated Au nanoparticles,

^{16}

could fill stretch-evoked interspaces between the particles to retain continuous electronic pathways. One-dimensional nanomaterials, such as Au nanowires,

^{17} Au

nanotubes

^{7, 18}

or carbon nanotubes (CNTs),

^{9, 19, 20}

could accommodate the applied strain by sliding and rotating against each other. However, the available materials that could be employed to construct stretchable electrodes are still very lacking, and the fabrication of stretchable electrodes usually involves demanding and timeconsuming processes to in situ synthesize these engineered nanomaterials.

^{716, 17}

Moreover, to monitor the very weak biochemical signals in the primary mechanotransduction, stretchable electrodes usually need further functionalization to improve their performance, such as sensitivity, selectivity or stretchability.

9, 13, 15, 19

Therefore, stretchable electrochemical sensors face with great challenges due to the limitation of both
至于可拉伸电极的制造，大多数报道的传感器都是基于精心设计的零维或一维纳米材料。高密度的零维纳米材料，如团聚金纳米粒子，

^{16}

可以填充粒子之间的拉伸间隙，从而保留连续的电子通路。一维纳米材料，如金纳米线、

^{17} Au

纳米管

^{7, 18}

或碳纳米管（CNT）

^{9, 19, 20}

，可以通过相互滑动和旋转来适应所施加的应变。然而，目前可用来构建可拉伸电极的材料仍然非常缺乏，而且制造可拉伸电极通常需要在原位合成这些工程纳米材料，工艺要求高，耗时长。

^{716, 17}

此外，为了监测初级机械传导中非常微弱的生化信号，可拉伸电极通常需要进一步功能化以提高其性能，如灵敏度、选择性或可拉伸性。

9, 13, 15, 19

因此，可拉伸电化学传感器面临着巨大的挑战，因为它们受到以下两方面的限制
electrode materials and processing techniques, and facile and versatile fabrication strategies are urgently needed to advance their applications.
电极材料和加工技术，以及简便、多功能的制造策略，这些都是推动其应用的迫切需要。

By virtue of high conductivity and good electrochemical performance, the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) commonly dispersed in poly(styrene sulfonate) (PSS) aqueous solution has been extensively used as an electrode material.

^{21 - 24}

However a low fracture strain (

\sim 5 %

) hinders the direct application of PEDOT:PSS film in stretchable electrodes. Many recent efforts have been devoted to increasing the stretchability by blending PEDOT:PSS with various additives, including elastomeric polymers and smallmolecule plasticizers.

^{25 - 27}

Generally, polymeric blends lead to worse conductivity due to the addition of insulating polymers.

^{28, 29}

Although small-molecule plasticizers (e.g. Zonyl

^{30}

and Triton X-100

^{31}

) could enhance both the elastic modulus and conductivity, the leaching of these toxic additives posed a threat to biological systems. Very recently, the doping of ionic liquids into PEDOT:PSS has achieved the coexistence of high stretchability and conductivity as well as satisfactory biocompatibility.

^{32, 33}

However, no impressive progress in stretchable electrodes based on PEDOT:PSS for electrochemical biosensing has been witnessed so far.
导电聚合物聚（3,4-亚乙二氧基噻吩）（PEDOT）通常分散在聚（苯乙烯磺酸盐）（PSS）水溶液中，具有高导电性和良好的电化学性能，因此被广泛用作电极材料。

^{21 - 24}

然而，低断裂应变（

\sim 5 %

）阻碍了 PEDOT:PSS 薄膜在可拉伸电极中的直接应用。最近，许多人致力于通过将 PEDOT:PSS 与各种添加剂（包括弹性聚合物和小分子增塑剂）混合来提高拉伸性。

^{25 - 27}

一般来说，聚合物混合物会因加入绝缘聚合物而导致导电性变差。

^{28, 29}

虽然小分子增塑剂（如 Zonyl

^{30}

和 Triton X-100

^{31}

）可以提高弹性模量和导电性，但这些有毒添加剂的浸出对生物系统构成威胁。最近，通过在 PEDOT:PSS 中掺入离子液体，实现了高拉伸性和导电性的共存以及令人满意的生物相容性。

^{32, 33}

然而，基于 PEDOT:PSS 的可拉伸电极在电化学生物传感方面迄今尚未取得令人瞩目的进展。

Herein, we report a facile method to fabricate a PEDOTbased stretchable electrochemical biosensor for the first time. The functionalized polymer was obtained by straightforwardly incorporating bis(trifluoromethane) sulfonimide lithium salt (LiTFSI) and cobalt phthalocyanine (CoPc) into PEDOT:PSS solution via simply mixing and stirring, forming the complex PEDOT:PSS-LiTFSI-CoPc (PPLC) (Scheme 1A). LiTFSI significantly improved the stretchability and conductivity of the PEDOT:PSS film, and CoPc endowed the film with excellent electrocatalytic property toward the oxidation of

H_{2} O_{2}

(a signaling molecule in diverse biological processes

^{34, 35}

). As a proof-of-concept, the stretchable PPLC/PDMS sensor was used
在此，我们首次报告了一种制造基于 PEDOT 的可拉伸电化学生物传感器的简便方法。通过简单的混合和搅拌，将双三氟甲烷磺酰亚胺锂盐（LiTFSI）和酞菁钴（CoPc）直接加入 PEDOT:PSS 溶液中，形成复合物 PEDOT:PSS-LiTFSI-CoPc (PPLC)（方案 1A），从而获得功能化聚合物。LiTFSI 明显改善了 PEDOT:PSS 薄膜的拉伸性和导电性，而 CoPc 则赋予了薄膜对

H_{2} O_{2}

（多种生物过程中的信号分子

^{34, 35}

）氧化的优异电催化性能。作为概念验证，使用了可拉伸的 PPLC/PDMS 传感器
to in situ load strains and simultaneously monitor mechanically induced

H_{2} O_{2}

release from human bronchial epithelial cells (Scheme 1B).
同时监测机械诱导的人类支气管上皮细胞

H_{2} O_{2}

释放（方案 1B）。

Results and discussion 结果和讨论

Fabrication and characterization of PPLC polymer
PPLC 聚合物的制造和表征

The functionalized PPLC polymer was obtained by simple blending of the plasticizer LiTFSI and catalyst CoPc with the solution of PEDOT:PSS. To investigate the microstructures of different polymer systems, PEDOT:PSS (PP), PEDOT:PSS-LiTFSI (PPL) and PPLC films were characterized by using an atomic force microscope (AFM). As a conductive polymer, PP dispersions are typically described as gel-like particles, which are composed of PEDOT-rich cores stabilized by PSS-rich shells in aqueous solvent

^{36, 37}

(Scheme 1A, left), and thus a large number of aggregated small grains appeared in the pristine PP film (Fig. 1A). Meanwhile, after being doped with the plasticizer LiTFSI, the polymer film processed distinct nanofibrous structures with good continuity (Fig. 1B). The morphological change is attributed to that LiTFSI can easily interact with both negatively charged PSS and positively charged PEDOT, and the weakened coulombic interaction between PSS and PEDOT chains allows PEDOT to decouple from the highly coiled PSS and grow into large-scale conducting domains, forming a continuous nanofiber network

^{33}

(Scheme 1A, right). Interestingly, the subsequent incorporation of catalyst CoPc molecules had little impact on the fibrous morphology (Fig. 1C), which will be beneficial for retaining the stable conductivity of the stretchable sensor.
功能化 PPLC 聚合物是通过将增塑剂 LiTFSI 和催化剂 CoPc 与 PEDOT:PSS 溶液简单混合而得到的。为了研究不同聚合物体系的微观结构，我们使用原子力显微镜（AFM）对 PEDOT:PSS（PP）、PEDOT:PSS-LiTFSI（PPL）和 PPLC 薄膜进行了表征。作为一种导电聚合物，PP分散体通常被描述为凝胶状颗粒，由富含PEDOT的核和富含PSS的壳组成，并稳定在水性溶剂

^{36, 37}

中（方案1A，左图），因此原始PP薄膜中出现了大量聚集的小颗粒（图1A）。同时，在掺入增塑剂 LiTFSI 后，聚合物薄膜形成了明显的纳米纤维结构，并具有良好的连续性（图 1B）。这种形态变化的原因是 LiTFSI 易于与带负电荷的 PSS 和带正电荷的 PEDOT 发生相互作用，PSS 和 PEDOT 链之间的库仑相互作用减弱，从而使 PEDOT 从高度卷曲的 PSS 中脱钩并生长为大尺度的导电畴，形成连续的纳米纤维网

^{33}

（方案 1A，右图）。有趣的是，随后加入的催化剂 CoPc 分子对纤维形态的影响很小（图 1C），这将有利于保持可拉伸传感器的稳定导电性。

Subsequently, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were performed to further characterize the composition of the PPLC/ PDMS film respectively. Compared with that of original PP, the FTIR spectrum of PPLC displayed characteristic absorption
随后，傅立叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）分别用于进一步表征 PPLC/ PDMS 薄膜的成分。与原始 PP 相比，PPLC 的傅立叶变换红外光谱显示出特征吸收

Scheme 1 (A) Schematic diagram representing the microstructures of traditional PEDOT:PSS (PP, left) and stretchable PEDOT:PSS (PPLC, right) functionalized with LiTFSI and CoPc. (B) Fabrication of a stretchable PPLC/PDMS film for monitoring cell mechanotransduction. (i) Spin-coating PPLC on PDMS. (ii) Cell seeding and culture. (iii) Electrochemical detection of

H_{2} O_{2}

release from stretched cells.
方案 1 (A) 传统 PEDOT:PSS（PP，左）和用 LiTFSI 和 CoPc 功能化的可拉伸 PEDOT:PSS（PPLC，右）的微结构示意图。(B) 制作用于监测细胞机械传导的可拉伸 PPLC/PDMS 薄膜。(i) 在 PDMS 上旋涂 PPLC。(ii) 细胞播种和培养。(iii) 拉伸细胞释放

H_{2} O_{2}

的电化学检测。

Fig. 1 AFM phase images of the (A) PP film, (B) PPL film and © PPLC film. (D) FTIR spectra of different materials. (E) XPS spectra of the PPLC film. (F) UV-visible spectra of different solutions.
图 1 (A) PP 薄膜、(B) PPL 薄膜和 © PPLC 薄膜的原子力显微镜相图。(D) 不同材料的傅立叶变换红外光谱。(E) PPLC 薄膜的 XPS 光谱。(F) 不同溶液的紫外可见光谱。
peaks assigned to the overlapping of the symmetric bending mode of

{CF}_{3}, C - S

and

S - N

stretching (

738 {cm}^{- 1}

), asymmetric bending mode of

{CF}_{3} (594 {cm}^{- 1})

and

C - C

stretching in isoindole (

1426 {cm}^{- 1}

), which were attributed to the existence of LiTFSI

^{38}

and

{CoPc}^{39}

in the functionalized PP , respectively (Fig. 1D). The full XPS spectrum of the PPLC film, together with the deconvolution of F 1s, Li 1s, Co 2p, C 1s, O 1s and S 2p spectra, demonstrated the presence of

F, Li, O, C, S

and Co elements (Fig. 1E and

S 1 †

), in which F and Li corresponded to LiTFSI and Co corresponded to CoPc, indicating the successful doping of LiTFSI and CoPc into the PPLC film.

^{40 - 42}

这些峰分别与异吲哚中的对称弯曲模式

{CF}_{3}, C - S

和

S - N

伸展（

738 {cm}^{- 1}

）、非对称弯曲模式

{CF}_{3} (594 {cm}^{- 1})

和

C - C

伸展（

1426 {cm}^{- 1}

）重叠，这归因于功能化 PP 中存在 LiTFSI

^{38}

和

{CoPc}^{39}

（图 1D）。PPLC 薄膜的全 XPS 光谱以及 F 1s、Li 1s、Co 2p、C 1s、O 1s 和 S 2p 光谱的解旋显示了

F, Li, O, C, S

和 Co 元素的存在（图 1E 和

S 1 †

），其中 F 和 Li 与 LiTFSI 相对应，Co 与 CoPc 相对应，这表明在 PPLC 薄膜中成功掺入了 LiTFSI 和 CoPc。

^{40 - 42}

Furthermore, UV-visible spectra were recorded to investigate the existing form of the catalyst CoPc in the PPLC film (Fig. 1F). Compared with that of PSS-LiTFSI-CoPc, the spectrum of PPLC showed that the existence of PEDOT made the peak corresponding to the B band of CoPc at 322 nm shift to 335 nm , and the peaks at 619 nm and 694 nm corresponding to the Q bands of CoPc shift to 635 nm and 724 nm , respectively.

^{43}

These red shifts in the spectrum revealed that CoPc molecules were assembled on the PEDOT chains via

π - π

interaction.
此外，还记录了紫外可见光谱，以研究催化剂 CoPc 在 PPLC 薄膜中的存在形式（图 1F）。与 PSS-LiTFSI-CoPc 的光谱相比，PPLC 的光谱显示，由于 PEDOT 的存在，CoPc 在 322 nm 处的 B 带峰移至 335 nm 处，CoPc 在 619 nm 和 694 nm 处的 Q 带峰分别移至 635 nm 和 724 nm 处。

^{43}

光谱中的这些红色偏移表明 CoPc 分子是通过

π - π

相互作用组装在 PEDOT 链上的。

Mechanical properties of the PPLC/PDMS electrode
PPLC/PDMS 电极的机械性能

To evaluate the mechanical properties of the PPLC-based sensor, a homogeneous mixture of PP, LiTFSI and CoPc was spin-coated on the surface of the PDMS film, which was pretreated with polydopamine to improve the wetting of PPLC solution. Due to the morphology of isolated grains, the fracture strain of the PP film is as low as

5 %

, because the grains will separate from each other and lead to a rapid decline in conductivity when strains are applied (Fig. S2A

†

). After introducing LiTFSI and CoPc, the electrostatic interaction between PEDOT and PSS could be greatly weakened, which resulted in the structure of conductive PEDOT-rich domains embedded in the soft PSS matrix, and this will theoretically improve the stable conductivity during stretching (Fig. 2A). Since the ionic liquid is the key to realizing the coexistence of high stretchability and conductivity, the amount of LiTFSI (

1 - 3 wt %

) in the
为了评估基于 PPLC 的传感器的机械性能，在 PDMS 薄膜表面旋涂了 PP、LiTFSI 和 CoPc 的均匀混合物，并用多巴胺对薄膜进行了预处理，以提高 PPLC 溶液的润湿性。由于孤立晶粒的形态，PP 薄膜的断裂应变低至

5 %

，因为在施加应变时晶粒会相互分离，导致电导率迅速下降（图 S2A

†

）。在引入 LiTFSI 和 CoPc 后，PEDOT 和 PSS 之间的静电作用会大大减弱，从而形成富含导电 PEDOT 的结构域，嵌入到软 PSS 基体中，这将在理论上提高拉伸过程中的稳定导电性（图 2A）。由于离子液体是实现高拉伸性和高导电性共存的关键，因此，LiTFSI（

1 - 3 wt %

）在拉伸过程中的用量应控制在 0.5%以下。

PPL film was optimized by comparing the cyclic voltammetric (CV) characteristics in

K_{3} [Fe (CN)_{6}]

(an electrochemical probe) solution (Fig. S3A

†

). The CV curves of PPL films with the additive of

2 wt %

and

3 wt %

LiTFSI had smaller potential differences than that of the PPL film doped with

1 wt %

LiTFSI, and they displayed very similar potential differences and electric capacities. Therefore, we chose

2 wt %

as the optimal additive amount in PP solution in principle of less addition of LiTFSI. Though the undeformed PPL/PDMS films spin-coated at a speed of

1000 rpm, 1500 rpm, 2000 rpm

and 3000 rpm had similar electrochemical performances (Fig. S3B

†

), the PPL/ PDMS film of 1500 rpm had the least cracks after recovering from being stretched to a strain of

50 %

and the most stable electrochemical performance (Fig. S4 and S5†). As a result, 2

wt %

LiTFSI and 1500 rpm speed for 60 s were selected as the optimal conditions for the fabrication of PPL/PDMS and PPLC/ PDMS films, and the thickness of spin-coated PPLC was approximately 400 nm (Fig.

S 6 †

). Besides, we examined the electrical conductivities of PPL and PPLC, and they were 1798.2

\pm 348.4

and

1036.2 \pm 120.5 S {cm}^{- 1}

, respectively. These results revealed that the doping of the ionic liquid LiTFSI dramatically improved the electrical conductivity of PP whose reported electrical conductivity is about

4 S {cm}^{- 1}

^{33}

通过比较

K_{3} [Fe (CN)_{6}]

（一种电化学探针）溶液中的循环伏安 (CV) 特性，对 PPL 薄膜进行了优化（图 S3A

†

）。添加了

2 wt %

和

3 wt %

LiTFSI 的 PPL 薄膜的 CV 曲线的电位差比掺杂了

1 wt %

LiTFSI 的 PPL 薄膜的 CV 曲线的电位差小，而且它们显示的电位差和电容量非常相似。因此，我们选择

2 wt %

作为聚丙烯溶液中的最佳添加量，原则是减少 LiTFSI 的添加量。虽然以

1000 rpm, 1500 rpm, 2000 rpm

和 3000 rpm 的速度旋涂的未变形 PPL/PDMS 薄膜具有相似的电化学性能（图 S3B

†

），但 1500 rpm 的 PPL/PDMS 薄膜在拉伸到

50 %

的应变恢复后裂纹最少，电化学性能最稳定（图 S4 和 S5†）。因此，我们选择 2

wt %

LiTFSI 和 1500 rpm 转速 60 s 作为制备 PPL/PDMS 和 PPLC/ PDMS 薄膜的最佳条件，旋涂 PPLC 的厚度约为 400 nm（图

S 6 †

）。此外，我们还检测了 PPL 和 PPLC 的电导率，它们分别为 1798.2

\pm 348.4

和

1036.2 \pm 120.5 S {cm}^{- 1}

。这些结果表明，离子液体 LiTFSI 的掺杂大大提高了聚丙烯的电导率，据报道聚丙烯的电导率约为

4 S {cm}^{- 1}

。

^{33}

To compare the stretchability of different films, the morphologies of PP, PPL and PPLC films were characterized after they were loaded with a series of tensile strains (10-100%) and then released to the original states. The pristine PP film obviously exhibited many wide vertical cracks (ca.

30 μ m

in width) after suffering from only

10 %

strain, and the cracks became sharply larger with the increase of mechanical strains (Fig. S2B

†

). In contrast, the surface of the PPL/PDMS film kept smooth even with a strain of

50 %

, and only few hairline cracks appeared when stretched up to 100% (Fig. S7,

†

top row). Scanning electron microscope (SEM) results showed that the PPL film maintained high integrality within the

50 %

strain, and uniform wrinkles and very few tiny cracks (ca. 500 nm in width) were observed under

100 %

strain due to the buckling of the PPL
为了比较不同薄膜的拉伸性，我们对 PP、PPL 和 PPLC 薄膜施加一系列拉伸应变（10%-100%）并恢复原状后的形态进行了表征。原始 PP 薄膜在仅承受

10 %

应变后明显出现许多宽垂直裂纹（宽度约

30 μ m

），并且随着机械应变的增加，裂纹急剧变大（图 S2B

†

）。相比之下，PPL/PDMS 薄膜的表面即使在应变

50 %

的情况下也能保持光滑，拉伸到 100%时也只出现了很少的毛细裂纹（图 S7，

†

顶行）。扫描电子显微镜（SEM）结果表明，PPL 薄膜在

50 %

应变范围内保持了较高的整体性，在

100 %

应变范围内，由于 PPL 的屈曲，观察到了均匀的皱纹和极少的微小裂纹（宽度约 500 nm）。

Fig. 2 (A) Schematic illustration showing the stretchability principle of the PPLC film. (B) Optical microscope (left) and SEM (right) images of the PPLC/PDMS film recovering from being submitted to various strains. Scale bar:

100 μ m

(black) and

10 μ m

(white). CVs of the PPLC/PDMS film obtained in

10 mM K_{3} [Fe (CN)_{6}] (C)

under different tensile strains and (D) after recovering from being bent at different radii (scan rate:

0.05 V s^{- 1}

). Statistical results of the CVs of PPLC/PDMS films obtained in

10 mM K_{3} [Fe (CN)_{6}]

after recovering from being (E) stretched to

50 %

and (F) bent at a radius of 3 mm for different cycles.
图 2 (A) PPLC 薄膜的拉伸原理示意图。(B) PPLC/PDMS 薄膜在受到各种应变后的光学显微镜（左）和扫描电子显微镜（右）图像。比例尺：

100 μ m

（黑色）和

10 μ m

（白色）。在

10 mM K_{3} [Fe (CN)_{6}] (C)

中获得的 PPLC/PDMS 薄膜在不同拉伸应变下的 CV 值，以及 (D) 以不同半径弯曲（扫描速率：

0.05 V s^{- 1}

）后恢复的 CV 值。在

10 mM K_{3} [Fe (CN)_{6}]

中得到的 PPLC/PDMS 薄膜在 (E) 拉伸到

50 %

和 (F) 以 3 mm 为半径弯曲不同周期后的 CV 统计结果。
composite (Fig. S7,† bottom row), manifesting that it was the LiTFSI additive that greatly improved the stretchability of the PPL film. As for the PPLC/PDMS film (Fig. 2A), similar to that of the PPL film, optical microscope images displayed that few short cracks appeared until the film was stretched up to

100 %

, and SEM images revealed that few perceptible wrinkles started to form when stretched to a strain of

50 %

(Fig. 2B and

S 8 †

). Whereas, the appeared cracks did not affect the overall continuity and stability of the PPLC film even under

100 %

strain.
复合材料（图 S7† 底行），这表明正是 LiTFSI 添加剂极大地改善了 PPL 薄膜的拉伸性。至于 PPLC/PDMS 薄膜（图 2A），与 PPL 薄膜类似，光学显微镜图像显示，在薄膜拉伸到

100 %

时，很少出现短裂纹，而扫描电镜图像显示，当拉伸到应变

50 %

时，开始形成一些可察觉的皱纹（图 2B 和

S 8 †

）。而出现的裂纹即使在

100 %

应变下也不会影响 PPLC 薄膜的整体连续性和稳定性。

To study the electrical stability of the PPLC-based stretchable sensor, the relative resistance

(Δ R / R_{0})

of the PPLC/PDMS film was recorded in the stretching-releasing cycle (

0 - 50 - 0 %

) and bending process, and no significant increase in

Δ R / R_{0}

occurred during the dynamic deformations, as well as stretching (

50 %

strain) and bending (a radius of 1 mm ) for 1000 cycles, respectively (Fig. S9†). The almost invariable resistance revealed the stable conductivity in the PPLC polymer. Then, to investigate the electrochemical stability, CVs of the PPLC/PDMS film in

K_{3} [Fe (CN)_{6}]

solution were collected after subjected to different mechanical deformations, including stretching to various tensile strains (

0 - 50 %

), bending with different radii (

0.5 - 12.5 mm

) and repeated loading. The potentials and peak currents of ferricyanide showed high consistency even when the PPLC/PDMS film was stretched with a strain of up to

90 %

(Fig. 2C) or bent with a small radius of 0.5 mm (Fig. 2D). Moreover, the currents of reduction

({ip}_{1})

and oxidation

({ip}_{2})

peaks and their potential differences (

Δ E_{p}

) of the recorded CVs were further analyzed after being repeatedly stretched to a strain of

50 %

and bent to a curvature radius of 3 mm for different cycles (Fig. 2E, F and S10

†

), and they had little change compared with the original undeformed states. The superior electrochemical stability is probably attributed to the percolation network of nanofibrous PEDOT:PSS, which could accommodate the applied strain by rotating and sliding against each
为了研究基于 PPLC 的可拉伸传感器的电稳定性，在拉伸-释放循环（

0 - 50 - 0 %

）和弯曲过程中记录了 PPLC/PDMS 薄膜的相对电阻

(Δ R / R_{0})

，在动态变形过程中，以及分别拉伸（

50 %

应变）和弯曲（半径为 1 mm）1000 次循环过程中，

Δ R / R_{0}

没有显著增加（图 S9†）。几乎不变的电阻表明 PPLC 聚合物具有稳定的导电性。然后，为了研究电化学稳定性，我们采集了

K_{3} [Fe (CN)_{6}]

溶液中的 PPLC/PDMS 薄膜在受到不同机械变形（包括拉伸到各种拉伸应变（

0 - 50 %

）、不同半径弯曲（

0.5 - 12.5 mm

）和重复加载）后的 CV 曲线。即使 PPLC/PDMS 薄膜受到高达

90 %

的应变拉伸（图 2C）或以 0.5 mm 的小半径弯曲（图 2D），铁氰化钾的电位和峰值电流也表现出高度的一致性。此外，在反复拉伸到应变

50 %

和弯曲到曲率半径为 3 mm 的不同周期后，进一步分析了记录的 CV 的还原

({ip}_{1})

和氧化

({ip}_{2})

峰的电流及其电位差 (

Δ E_{p}

) （图 2E、F 和 S10

†

），它们与原始未变形状态相比变化不大。优异的电化学稳定性可能归功于纳米纤维状 PEDOT:PSS 的渗滤网络，它可以通过旋转和相互滑动来适应所施加的应变。
other. The slight increase in ip and

Δ E_{p}

in the case of higher strain (e.g. 90%) or being recovered from stretching for more cycles might be attributed to a combined result of more exposed PEDOT:PSS nanofibers (larger electrode area and ip) and some irreversible interlacement with others (higher electrical resistivity and

Δ E_{p}

). Overall, these results clearly demonstrated the excellent electrochemical stability of the PPLC-based stretchable electrode against mechanical deformations.
其他。在拉伸应变较大（如 90%）或拉伸循环次数较多的情况下，ip 和

Δ E_{p}

略有增加，这可能是 PEDOT:PSS 纳米纤维暴露较多（电极面积和 ip 较大）以及与其他纳米纤维发生不可逆置换（电阻率和

Δ E_{p}

较高）的综合结果。总之，这些结果清楚地表明，基于 PPLC 的可拉伸电极具有出色的电化学稳定性，能够抵御机械变形。

Moreover, compared with other electrode materials of stretchable electrochemical sensors, the prominent feature of water-soluble PPLC is the high processability, and many processing techniques could be employed for convenient, controllable and high-throughput electrode fabrication. For example, the pattern and size of the PPLC-based electrode could be easily regulated with the aid of photolithography or an ink-jet printer (Fig. S11†). Convincingly, the superb processibility will make PPLC hold great potential application in various flexible and stretchable sensors.
此外，与其他可拉伸电化学传感器的电极材料相比，水溶性 PPLC 的突出特点是可加工性强，可采用多种加工技术方便、可控、高通量地制造电极。例如，可以借助光刻技术或喷墨打印机轻松调节基于 PPLC 的电极的图案和尺寸（图 S11†）。令人信服的是，PPLC 极佳的可加工性将使其在各种柔性和可拉伸传感器中拥有巨大的应用潜力。

Electrochemical sensing performance of the PPLC/PDMS film
PPLC/PDMS 薄膜的电化学传感性能

The electrochemical performance of the PPLC/PDMS film was studied after the confirmation of its mechanical stability. Compared with the PP/PDMS electrode, the electrochemical performance of the PPL/PDMS electrode was greatly improved because of the increased conductivity caused by doping LiTFSI. The CV of the PPLC/PDMS electrode was almost the same as that of the PPL/PDMS film, which indicated that the addition of CoPc had little effect on the electron transfer in the original PPL/PDMS electrode (Fig. 3A). Meanwhile, as an electron mediator, CoPc could endow the electrode with remarkable sensing ability by catalyzing the target molecules involved in cell activities, such as the oxidation of

H_{2} O_{2}

O_{2}

via a redox reaction between

{Co}^{II} Pc

and

{Co}^{III} Pc

(Fig. 3B).

^{44}

It was observed
在确认了 PPLC/PDMS 薄膜的机械稳定性之后，对其电化学性能进行了研究。与 PP/PDMS 电极相比，PPL/PDMS 电极的电化学性能因掺杂 LiTFSI 后电导率的提高而大大改善。PPLC/PDMS 电极的 CV 值与 PPL/PDMS 薄膜的 CV 值基本相同，这表明 CoPc 的加入对原 PPL/PDMS 电极的电子传递影响很小（图 3A）。同时，作为电子介质，CoPc 可以催化参与细胞活动的目标分子，如通过

{Co}^{II} Pc

和

{Co}^{III} Pc

之间的氧化还原反应将

H_{2} O_{2}

氧化为

O_{2}

，从而赋予电极显著的传感能力（图 3B）。

^{44}

据观察

Fig. 3 (A) CVs of different electrodes obtained in

10 mM K_{3} [Fe (CN)_{6}]

. Inset: the enlarged view for CV of the PP electrode. (B) Schematic illustration of the electrocatalysis mechanism. © CVs of different electrodes with and without

1 mM H_{2} O_{2}

. ( D ) Amperometric responses of PPL/ PDMS (black lines) and PPLC/PDMS (red lines) electrodes to

H_{2} O_{2}

at a potential of +0.55 V (vs.

Ag / AgCl)

to increasing

H_{2} O_{2}

concentrations. Inset: the enlargements of amperometric responses framed in blue. (E) Calibration curves of PPL/PDMS and PPLC/PDMS electrodes to increasing

H_{2} O_{2}

concentrations (data presented as mean

\pm

standard error,

n = 3

). (F) Calculated LOD and sensitivity of PPL/PDMS and PPLC/PDMS electrodes to

H_{2} O_{2}

.
图 3 (A) 在

10 mM K_{3} [Fe (CN)_{6}]

中获得的不同电极的 CV 值。插图：PP 电极的 CV 放大图。(B) 电催化机理示意图。(C) 有

1 mM H_{2} O_{2}

和没有

1 mM H_{2} O_{2}

的不同电极的 CV 值。( D ) PPL/ PDMS（黑线）和 PPLC/PDMS（红线）电极在 +0.55 V 电位下对

H_{2} O_{2}

的安培反应（与

Ag / AgCl)

对

H_{2} O_{2}

浓度增加的反应对比）。插图：蓝色框内的安培反应放大图。 (E) PPL/PDMS 和 PPLC/PDMS 电极对

H_{2} O_{2}

浓度增加的校准曲线（数据以平均值

\pm

标准误差、

n = 3

表示）。(F) PPL/PDMS 和 PPLC/PDMS 电极对

H_{2} O_{2}

的计算 LOD 和灵敏度。
that the CV curve obtained in

H_{2} O_{2}

solution of the PPLC/PDMS electrode showed an obvious oxidation peak at +0.55 V (Fig. 3C), while the response of the PPL/PDMS electrode in

H_{2} O_{2}

was almost identical to that in phosphate buffered solution (PBS), manifesting the excellent catalysis of CoPc molecule towards

H_{2} O_{2}

oxidation. Since the sensing performance was ascribed to the catalyst CoPc , the additive amount of

CoPc (0 - 50 mM)

in the PPLC polymer system was optimized by comparing the CV responses of different PPLC/PDMS electrodes to

1 mM H_{2} O_{2}

(Fig.

S 12 †

). The current responses caused by

H_{2} O_{2}

oxidation increased with the increase of CoPc contents and reached a peak at a level of 20 mM , and the declining response at a concentration of 25 mM or even higher probably resulted from the formation of CoPc precipitates

^{45}

with low electrocatalytic efficiency towards

H_{2} O_{2}

oxidization.
在

H_{2} O_{2}

溶液中，PPLC/PDMS 电极的 CV 曲线在 +0.55 V 处出现了一个明显的氧化峰（图 3C），而 PPL/PDMS 电极在

H_{2} O_{2}

溶液中的响应几乎与磷酸盐缓冲溶液 (PBS) 中的响应相同，这表明 CoPc 分子对

H_{2} O_{2}

氧化具有良好的催化作用。由于传感性能归功于催化剂 CoPc，因此通过比较不同 PPLC/PDMS 电极对

1 mM H_{2} O_{2}

的 CV 响应，优化了

CoPc (0 - 50 mM)

在 PPLC 聚合物体系中的添加量（图

S 12 †

）。由

H_{2} O_{2}

氧化引起的电流响应随着 CoPc 含量的增加而增加，并在 20 mM 水平达到峰值，而在 25 mM 或更高浓度时响应下降，这可能是由于形成了对

H_{2} O_{2}

氧化具有低电催化效率的 CoPc 沉淀

^{45}

。

The superiority of CoPc molecules to

H_{2} O_{2}

electrooxidation was further demonstrated by the amperometric responses to a series of

H_{2} O_{2}

solutions with increasing concentrations. The PPLC/PDMS electrode could respond sensitively to 200 nM

H_{2} O_{2}

(Fig. 3D, red lines) and exhibit a good linear relationship with

H_{2} O_{2}

in a wide concentration range from 200 nM to

50 μ M

(Fig. 3E). Conversely, the PPL/PDMS electrode generated a detectable signal until the concentration of

H_{2} O_{2}

increased to as high as

20 μ M

(Fig. 3D, black lines). The calculated detection limit (LOD) of the PPLC/PDMS electrode was

95 nM (S / N = 3

), which was approximately 200 -fold lower than that of the PPL/ PDMS electrode ( 17800 nM ), and the sensitivity of the PPLC/ PDMS electrode (

220 nA μ M^{- 1} {cm}^{- 2}

) was about 560 -fold higher than that of the PPL/PDMS electrode (

0.395 nA μ M^{- 1} {cm}^{- 2}

) (Fig. 3F). In addition, we recorded the CV responses of the PPLC/PDMS electrode to

1 mM H_{2} O_{2}

and the amperometric
CoPc 分子对

H_{2} O_{2}

电氧化作用的优越性进一步体现在对一系列浓度不断增加的

H_{2} O_{2}

溶液的安培反应上。PPLC/PDMS 电极可以灵敏地响应 200 nM 的

H_{2} O_{2}

（图 3D，红线），并在 200 nM 到

50 μ M

的宽浓度范围内与

H_{2} O_{2}

呈现出良好的线性关系（图 3E）。相反，PPL/PDMS 电极在

H_{2} O_{2}

浓度增加到

20 μ M

时才产生可检测信号（图 3D，黑线）。经计算，PPLC/PDMS电极的检测限（LOD）为

95 nM (S / N = 3

，比PPL/PDMS电极（17800 nM）低约200倍，而PPLC/PDMS电极的灵敏度（

220 nA μ M^{- 1} {cm}^{- 2}

）比PPL/PDMS电极（

0.395 nA μ M^{- 1} {cm}^{- 2}

）高约560倍（图3F）。此外，我们还记录了 PPLC/PDMS 电极对

1 mM H_{2} O_{2}

的 CV 响应和对

0.395 nA μ M^{- 1} {cm}^{- 2}

的安培响应（图 3F）。
responses of this electrode to a series of

H_{2} O_{2}

solutions before deformation and after recovering from being repeatedly stretched to a strain of

50 %

(Fig. S13†), and the almost perfectly consistent curves indicated that the repeated deformations had little negative influence on the

H_{2} O_{2}

sensing performance.
图 S13†），曲线几乎完全一致，表明反复变形对

H_{2} O_{2}

传感性能几乎没有负面影响。

Real-time monitoring of stretch-induced $H_{2} O_{2}$ released from 16HBECs
实时监测拉伸引起的 16HBECs $H_{2} O_{2}$ 释放情况

As an important signaling molecule,

H_{2} O_{2}

is strongly implicated in cell proliferation, aging, death and signal transduction, and the levels of

H_{2} O_{2}

can reflect the normal or abnormal conditions of living organisms.

^{34, 35}

Recently increasing studies have revealed that the production of

H_{2} O_{2}

is also regulated by mechanical forces exposed on cells or organs via mechanotransduction, besides the inherent cell metabolism.

^{46 - 48}

Exemplarily, the secretions of lung cells are regulated by mechanical stretch under both physiological (breathing) and pathophysiological (ventilator-induced) conditions,

^{49 - 51}

and the content of exhaled

H_{2} O_{2}

was elevated in the lungs of patients with bronchiectasis.

^{52 - 54}

Considering that the dynamic changes of

H_{2} O_{2}

concentration emitted from lung cells have been poorly studied, the PPLC/PDMS electrode was employed as a platform for realtime monitoring of stretch-induced

H_{2} O_{2}

release from human bronchial epithelial cells (16HBECs) under different strains (Fig. 4A).
作为一种重要的信号分子，

H_{2} O_{2}

与细胞增殖、衰老、死亡和信号转导密切相关，

H_{2} O_{2}

的水平可以反映生物体的正常或异常状况。

^{34, 35}

最近越来越多的研究发现，

H_{2} O_{2}

的产生除了受细胞固有新陈代谢的影响外，还受到暴露在细胞或器官上的机械力通过机械传导的调节。

^{46 - 48}

例如，在生理（呼吸）和病理生理（呼吸机诱发）条件下，肺细胞的分泌物都会受到机械拉伸的调节，

^{49 - 51}

支气管扩张患者肺部呼出的

H_{2} O_{2}

含量也会升高。

^{52 - 54}

考虑到对肺细胞释放的

H_{2} O_{2}

浓度的动态变化研究较少，我们采用PPLC/PDMS电极作为平台，实时监测不同应变下人支气管上皮细胞（16HBECs）在拉伸诱导下释放的

H_{2} O_{2}

（图4A）。

Firstly, the biocompatibility should be taken into account due to the direct contact between the sensor and living cells, and this is a particularly important issue since two additives were added into the PPLC compared with the native PP form. It was expressly observed that 16HBECs could attach well onto the surface of the PPLC film with the pseudopodia outspread fully
首先，由于传感器与活细胞直接接触，因此应考虑生物相容性，这一点尤为重要，因为与原生 PP 相比，PPLC 中添加了两种添加剂。据明确观察，16HBEC 可以很好地附着在 PPLC 薄膜表面，其假足完全张开。

Fig. 4 (A) Schematic diagram of cellular mechanotransduction in stretched 16HBECs. (B) SEM image of 16HBECs cultured on a PPLC/PDMS film for 4 h . © Fluorescence microscopic images of 16HBECs cultured on a PPLC/PDMS film stained with Calcein-AM (green) and PI (red) before and after being stretched. Amperometric responses (D) and the corresponding statistical results (E) detected from 16HBECs submitted to different stretch stimuli (applied potential: +0.55 V vs.

Ag / AgCl

, data presented as mean

\pm

standard error,

n = 6, P

-values were calculated using one-way ANOVA,

^{* * P} < 0.01, * * * P < 0.001

). (F) Amperometric responses detected from 16 HBECs submitted to

30 %

strain with different treatments at a potential of +0.55 V (vs.

Ag / AgCl)

. Inset: corresponding normalized statistical results of amperometric responses recorded from cells stimulated with only strain (red cylinder) and cells pretreated with L-NMMA (blue cylinder) (data presented as mean

\pm

standard error,

n = 4, P

-values were calculated using one-way ANOVA, n.s.: no significance). The vertical gray dashed lines in (D) and (F) indicated the beginning of the stretch stimuli; the hauling speed was

0.85 mm s^{- 1}

.
图 4 (A) 拉伸 16HBECs 的细胞机械传导示意图。 (B) 在 PPLC/PDMS 薄膜上培养 4 小时的 16HBECs 的扫描电镜图像。在 PPLC/PDMS 薄膜上培养的 16HBECs 在拉伸前后的荧光显微图像，分别用 Calcein-AM （绿色）和 PI （红色）染色。在不同拉伸刺激下（外加电位：+0.55 V vs. <0.55 V），16HBECs 检测到的安培反应（D）和相应的统计结果（E）：+数据以平均值

\pm

标准误差表示，

n = 6, P

值使用单因素方差分析计算，

^{* * P} < 0.01, * * * P < 0.001

）。(F）在+0.55 V的电位下，从16个HBECs检测到的不同处理的

30 %

应变的安培反应（与

Ag / AgCl)

对比。插图：仅用应变刺激的细胞（红色圆柱）和用 L-NMMA 预处理的细胞（蓝色圆柱）记录的安培反应的相应归一化统计结果（数据以平均值

\pm

标准误差表示，

n = 4, P

值使用单因素方差分析计算，n.s. ：无显著性）。(D) 和 (F) 中的垂直灰色虚线表示拉伸刺激的开始；牵引速度为

0.85 mm s^{- 1}

。
after being cultured thereon for 4 h (Fig. 4B). Thereafter, 16HBECs were cultured on the PPLC/PDMS film for

6 h, 24 h, 48

h and 96 h (Fig. S14

†

), until they proliferated and covered almost all over the electrode. The staining by live/dead cell markers

3^{'}, 6^{'}

-di

(o -

acetyl

) - 4^{'}, 5^{'}

-bis[

N, N

-bis(carboxymethyl)-aminomethyl] fluorescein, tetraacetoxymethylester (Calcein-AM) and propidium iodide (PI) revealed that all cells kept high viability after being cultured for up to 96 h (Fig. S14E

†

). The satisfactory biocompatibility demonstrated that the added plasticizer LiTFSI and catalyst CoPc have little effect on the original cytocompatibility of PP.
图 4B）。此后，在 PPLC/PDMS 薄膜上分别培养 16HBECs

6 h, 24 h, 48

h 和 96 h（图 S14

†

），直到它们增殖并几乎覆盖整个电极。活/死细胞标记

3^{'}, 6^{'}

-二

(o -

乙酰基

) - 4^{'}, 5^{'}

-双[

N, N

-双（羧甲基）-氨基甲基]荧光素、四乙酰氧甲基酯（Calcein-AM）和碘化丙啶（PI）的染色结果表明，所有细胞在培养长达 96 小时后都保持了很高的活力（图 S14E

†

）。令人满意的生物相容性表明，添加的增塑剂 LiTFSI 和催化剂 CoPc 对 PP 原有的细胞相容性影响很小。

Before the monitoring of mechanotransduction, the normal metabolism activity of 16HBECs cultured on the PPLC/PDMS electrode was examined. After the cells were stimulated with phorbol 12-myristate 13-acetate (PMA),

^{55}

which could activate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (the main enzyme for ROS production in the cells), a rapid increase in the current was detected by the PPLC/PDMS electrode (Fig. S15,

†

red line). When catalase (

H_{2} O_{2}

scavenger) was added together with PMA, the current decreased significantly (Fig. S15, † blue line). The above results indicated that the PPLC/PDMS electrode had the ability of real-time monitoring of

H_{2} O_{2}

release from 16HBECs. Subsequently, the electrode bearing 16HBECs was submitted to a tensile strain of about

35 %

to fully cover the physiological (

5 - 15 %

) and pathological strain ranges (20-30%) of lung cells,

^{49, 56}

and the fluorescence staining of Calcein-AM and PI revealed that the cells still adhered firmly to the substrate and remained perfectly alive during the stretching process (Fig. 4C).
在监测机械传导之前，先检测了在 PPLC/PDMS 电极上培养的 16HBECs 的正常代谢活动。当细胞受到可激活烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶（细胞中产生 ROS 的主要酶）的 12-肉豆蔻酸 13-醋酸酯（PMA）

^{55}

刺激后，PPLC/PDMS 电极检测到电流迅速增加（图 S15，

†

红线）。当过氧化氢酶（

H_{2} O_{2}

清除剂）与 PMA 同时加入时，电流明显下降（图 S15，† 蓝线）。上述结果表明，PPLC/PDMS电极具有实时监测16HBECs中

H_{2} O_{2}

释放的能力。随后，将带有16HBECs的电极置于约

35 %

的拉伸应变下，以完全覆盖肺细胞的生理应变（

5 - 15 %

）和病理应变范围（20%-30%），

^{49, 56}

，钙黄绿素-AM和PI的荧光染色显示，细胞在拉伸过程中仍然牢牢地粘附在基底上，并保持完全存活（图4C）。

Then, the PPLC/PDMS electrode with 16HBECs cultured thereon was loaded with different stretching stimuli to model natural (

10 %

strain) and bronchiectasis (

20 %

and

30 %

strain) conditions.

^{56}

It was observed that the ampere-currents rose upon the stretching stimuli (Fig. 4D), and the increases of ampere-currents were proportional to the incremental mechanical strains (Fig. 4D, red line). To confirm that the increased current was caused by

H_{2} O_{2}

release from the cells triggered by mechanical stimuli, 16HBECs were submitted to the same strains after being pre-treated with catalase and diphenyleneiodonium chloride (DPI, a widely used NADPH oxidase inhibitor), respectively. The results showed that the recorded current increases from cells pre-treated with catalase (Fig. 4D, blue line) were obviously smaller than those from cells with only mechanical stimuli (Fig. 4D, red line), and pre-treating with DPI further decreased the current responses due to the inhibition of NADPH oxidase (Fig. 4D, purple line). Altogether, these results revealed that the rise of ampere-current was evoked by

H_{2} O_{2}

release via the activation of NADPH oxidase in response to mechanical stretch. Besides, the production of

H_{2} O_{2}

in 16HBECs caused by mechanical strain was also verified through staining with DCFH-DA (a ROS fluorescent probe) (Fig. S16†).
然后，对培养有16HBECs的PPLC/PDMS电极施加不同的拉伸刺激，以模拟自然条件（

10 %

应变）和支气管扩张条件（

20 %

和

30 %

应变）。

^{56}

据观察，在拉伸刺激下，安培电流上升（图 4D），安培电流的增加与机械应变的增加成正比（图 4D，红线）。为了证实电流的增加是由机械刺激引发的

H_{2} O_{2}

从细胞中释放所致，16HBECs在分别用过氧化氢酶和二苯基碘氯化铵（DPI，一种广泛使用的NADPH氧化酶抑制剂）预处理后被置于相同的应变下。结果表明，用过氧化氢酶预处理的细胞记录到的电流增加（图 4D 蓝线）明显小于只受机械刺激的细胞记录到的电流增加（图 4D 红线），而用 DPI 预处理会进一步降低电流反应，因为 NADPH 氧化酶被抑制了（图 4D 紫线）。总之，这些结果表明，安培电流的上升是在机械拉伸作用下通过激活 NADPH 氧化酶释放

H_{2} O_{2}

引起的。此外，用 DCFH-DA（一种 ROS 荧光探针）染色也验证了机械拉伸导致 16HBECs 中

H_{2} O_{2}

的产生（图 S16†）。

Considering that the sudden mechanical disturbance resulted in reasonable noise (Fig. 4D, black line), the currents recorded by the electrode under the same strains without cells cultured thereon were taken as the baseline for the statistical analysis of the above results. As clearly shown in Fig. 4E, the amount of stretch-evoked

H_{2} O_{2}

release increased with stretching magnitudes, and the scavenging of released

H_{2} O_{2}

by
考虑到突然的机械干扰会产生合理的噪声（图 4D，黑线），我们将电极在相同应变下记录到的未培养细胞的电流作为基线，对上述结果进行统计分析。如图 4E 所示，拉伸诱发的

H_{2} O_{2}

释放量随拉伸幅度的增加而增加，而

H_{2} O_{2}

对

H_{2} O_{2}

释放量的清除量则随拉伸幅度的增加而增加。
catalase made the recorded current sharply decrease, and the inhibition of NADPH oxidase activity by DPI resulted in a negligible current response. The concentrations of emitted

H_{2} O_{2}

from 16 HBECs under

10 %, 20 %

and

30 %

strains were calculated to be

4.90 \pm 3.00 μ M (10 %), 11.20 \pm 3.60 μ M (20 %)

and

22.00 \pm 1.50 μ M (30 %)

, respectively, which were consistent with previous studies that much more

H_{2} O_{2}

molecules were released under bronchiectasis than normal condition.

^{52 - 54}

过氧化氢酶使记录到的电流急剧下降，而 DPI 对 NADPH 氧化酶活性的抑制导致电流反应微乎其微。经计算，16个HBECs在

10 %, 20 %

和

30 %

菌株下释放的

H_{2} O_{2}

浓度分别为

4.90 \pm 3.00 μ M (10 %), 11.20 \pm 3.60 μ M (20 %)

和

22.00 \pm 1.50 μ M (30 %)

，这与之前的研究一致，即支气管扩张时释放的

H_{2} O_{2}

分子比正常情况下多很多。

^{52 - 54}

In 16HBEC mechanotransduction, NO is another closely related signaling molecule revealed by our previous sensor at a potential of

+ 0.8 V,^{9}

while most of NO molecules could not be oxidized under the potential of +0.55 V for the electrooxidation of

H_{2} O_{2}

(Fig.

S 17 †

). This viewpoint was further validated by cell experiments, in which the current response recorded from those treated with L-NMMA (a total nitric oxide synthase inhibitor) showed no significant decrease, while pre-treatment with DPI led to a dramatic fall in the current response, comparable to that of cells under only mechanical strain (Fig. 4F). These results explicitly indicated that the current increase was caused by the electrooxidation of stretch-evoked

H_{2} O_{2}

rather than NO under the potential of +0.55 V . Taken together, the above results demonstrated that the LiTFSI and CoPc functionalized PP concurrently possessed excellent stretchability and electrochemical sensing, as well as high biocompatibility, which allowed mimicking the bronchiectasis and synchronously real-time monitoring of stretch-induced

H_{2} O_{2}

release from 16HBECs.
在 16HBEC 机械传导过程中，NO 是另一种密切相关的信号分子，我们之前的传感器在

+ 0.8 V,^{9}

电位下揭示了这一分子，而在电氧化

H_{2} O_{2}

的 +0.55 V 电位下，大多数 NO 分子无法被氧化（图

S 17 †

）。细胞实验进一步验证了这一观点，其中用 L-NMMA（一氧化氮合酶完全抑制剂）处理的细胞记录到的电流响应没有明显下降，而用 DPI 预处理则导致电流响应急剧下降，与只承受机械应变的细胞的电流响应相当（图 4F）。这些结果明确表明，在+0.55 V的电位下，电流增加是由拉伸诱发的

H_{2} O_{2}

电氧化引起的，而不是由NO引起的。综上所述，LiTFSI 和 CoPc 功能化聚丙烯同时具有优异的拉伸性和电化学传感能力，以及较高的生物相容性，可以模拟支气管扩张并同步实时监测拉伸诱导的 16HBECs

H_{2} O_{2}

释放。

Conclusions 结论

In summary, we have developed an efficient strategy for constructing a conductive polymer-based stretchable electrochemical sensor (PPLC/PDMS) via facile blending LiTFSI and CoPc with PEDOT:PSS. The doping of LiTFSI distinctly enhanced both conductivity and stretchability, and the incorporation of CoPc enabled the sensor to sensitively detect

H_{2} O_{2}

molecules. With excellent mechanical and electrochemical performance, as well as satisfactory biocompatibility, the PPLC/ PDMS sensor has successfully achieved in situ inducing and simultaneous monitoring of

H_{2} O_{2}

release from stretched 16HBECs. In this work, we focused on the application of stretchable PEDOT film in real-time monitoring of cell mechanotransduction. Considering the high accessibility and versatility of the preparation method, plenty of conductive polymers with specific functionality could be obtained by altering the plasticizer or catalyst. Therefore, the proposed strategy is expected to offer numerous opportunities for polymer-based wearable and stretchable sensors with practical applications in biomedical sciences and healthcare monitoring.
总之，我们开发了一种高效的策略，通过将 LiTFSI 和 CoPc 与 PEDOT:PSS 简单混合，构建了基于导电聚合物的可拉伸电化学传感器（PPLC/PDMS）。LiTFSI 的掺杂明显提高了导电性和拉伸性，而 CoPc 的加入则使传感器能够灵敏地检测

H_{2} O_{2}

分子。PPLC/ PDMS 传感器具有优异的机械和电化学性能以及令人满意的生物相容性，成功实现了原位诱导和同时监测拉伸 16HBECs 中

H_{2} O_{2}

的释放。在这项工作中，我们重点研究了可拉伸 PEDOT 薄膜在实时监测细胞机械传导中的应用。考虑到制备方法的高易用性和多功能性，通过改变增塑剂或催化剂可以获得大量具有特定功能的导电聚合物。因此，所提出的策略有望为基于聚合物的可穿戴和可拉伸传感器提供大量机会，并在生物医学科学和医疗保健监测领域得到实际应用。

Experimental 实验性

Materials and methods 材料和方法

PEDOT:PSS (Clevios PH1000) was purchased from Wuhan Zhuojia Technology Co., Ltd. (Wuhan, China). The PDMS prepolymer and cross-linker were obtained from Momentive Performance Materials (Waterford, NY, U.S.A.). Dopamine
PEDOT:PSS (Clevios PH1000) 购自武汉卓佳科技有限公司（中国武汉）。(中国武汉）。PDMS 预聚物和交联剂购自 Momentive Performance Materials 公司（美国纽约沃特福德）。多巴胺
hydrochloride and bis(trifluoromethane) sulfonimide lithium salt (LiTFSI) were bought from Sigma Aldrich (St. Louis, U.S.A.). Cobalt phthalocyanine (CoPc) was purchased from Aladdin Industrial Co., Ltd. (Shanghai, China). The negative photoresist SU-8 and developer were bought from MicroChem Corp (Massachusetts, U.S.A.). 16HBECs were obtained from Shanghai Sixin Biotechnology Co., Ltd. (Shanghai, China). Fetal bovine serum (FBS), RPMI-1640 culture medium, and trypsin-EDTA (

0.25 %

) were bought from GIBCO Corporation (U.S.A.). CalceinAM, PI, PMA and DPI (NADPH oxidase inhibitor) were obtained from Sigma Aldrich (St. Louis, U.S.A.). DCFH-DA (ROS fluorescent probe), L-NMMA (a total nitric oxide synthase inhibitor) and catalase were bought from Beyotime Biotechnology (Shanghai, China). Ultrapure water (Millipore,

18 M Ω {cm}^{- 1}

) was used throughout the experiments.
盐酸盐和双三氟甲烷磺酰亚胺锂盐（LiTFSI）购自 Sigma Aldrich 公司（美国圣路易斯）。酞菁钴（CoPc）购自阿拉丁实业有限公司（中国上海）。(中国上海）购买。负片光刻胶 SU-8 和显影剂购自 MicroChem 公司（美国马萨诸塞州）。16HBECs 购自上海思新生物科技有限公司（中国上海）。(中国上海）。胎牛血清（FBS）、RPMI-1640 培养基和胰蛋白酶-EDTA (

0.25 %

) 购自美国 GIBCO 公司。CalceinAM、PI、PMA 和 DPI（NADPH 氧化酶抑制剂）购自 Sigma Aldrich 公司（美国圣路易斯）。DCFH-DA（ROS 荧光探针）、L-NMMA（一氧化氮合酶总抑制剂）和过氧化氢酶购自贝因美生物技术公司（中国上海）。实验全程使用超纯水（Millipore，

18 M Ω {cm}^{- 1}

）。

AFM images were recorded in tapping mode using a BioScope Resolve Atomic Force Microscope (Bruker, Germany). UVvis absorption spectra were conducted on a UV-2550 spectrophotometer (Shimadzu, Japan). XPS measurements were performed on an ESCALAB 250Xi photoelectron spectrometer (Fisher Scientific, U.S.A.) by using

Al K α X

-ray radiation as the Xray excitation source. FTIR spectra were recorded on a NICOLET FTIR5700 Fourier transform infrared spectrometer (Thermo, U.S.A.). SEM images were obtained by a Merlin compact fieldemission scanning electron microscope (Zeiss, Germany). The inkjet printing was conducted by a Jetlab4 XL-A inkjet printer (MicroFab, U.S.A.). The photolithography was performed by a G17 lithography machine (Chengdu, China). All the microscopic observation and fluorescence imaging were implemented by an Axiovert 200M and Axio Observer Z1 inverted fluorescent microscope (Zeiss, Germany). All electrochemical measurements were conducted on a CHI 660A electrochemical workstation (CHI-Instruments, Shanghai) with Pt counter electrode and

Ag / AgCl

reference electrode at room temperature.
使用 BioScope Resolve 原子力显微镜（德国布鲁克公司）以攻丝模式记录原子力显微镜图像。紫外可见吸收光谱在 UV-2550 分光光度计（日本岛津）上进行。XPS 测量在 ESCALAB 250Xi 光电子能谱仪（Fisher Scientific，美国）上进行，使用

Al K α X

射线辐射作为 X 射线激发光源。傅立叶变换红外光谱由 NICOLET FTIR5700 傅立叶变换红外光谱仪（Thermo，美国）记录。扫描电子显微镜图像由 Merlin 紧凑型场发射扫描电子显微镜（德国蔡司公司）获得。喷墨打印由 Jetlab4 XL-A 喷墨打印机（MicroFab，美国）完成。光刻由 G17 光刻机（中国成都）完成。所有显微观察和荧光成像均由 Axiovert 200M 和 Axio Observer Z1 倒置荧光显微镜（蔡司，德国）完成。所有电化学测量均在 CHI 660A 电化学工作站（CHI-Instruments，上海）上进行，铂对电极和

Ag / AgCl

参比电极均在室温下进行。

Fabrication of the PPLC/PDMS film
制作 PPLC/PDMS 薄膜

Firstly, a PDMS film was acquired by spin-coating the degassed liquid prepolymer and cross-linker (

w / w = 10 : 1

) on a Si substrate at a spin rate of 1000 rpm for 10 s and thermally cured at

80^{\circ} C

for 3 h . Then, the PDMS film was immersed in dopamine hydrochloride solution (

1 mg {mL}^{- 1}

, Tris-HCl buffer solution, 10 mM , and

pH \sim 8.5

) for 24 h to enhance its hydrophilicity. For the synthesis of PPLC polymer, LiTFSI (

2 wt %

) and

CoPc (20 mM

) were added to the PP aqueous dispersion (1 wt%), and stirred vigorously at 1000 rpm for 6 h . Then, the homogeneous mixture solution was spin-coated on the polydopaminecoated PDMS film at a spin rate of 1500 rpm for 60 s , and then annealed at

130^{\circ} C

for 15 min , forming the PPLC/PDMS film.
首先，将脱气的液态预聚物和交联剂（

w / w = 10 : 1

）以 1000 rpm 的旋转速度在硅基底上旋转涂布 10 秒，获得 PDMS 薄膜，并在

80^{\circ} C

下热固化 3 小时。然后，将 PDMS 薄膜浸入盐酸多巴胺溶液（

1 mg {mL}^{- 1}

，Tris-HCl 缓冲溶液，10 mM，

pH \sim 8.5

）中 24 小时，以增强其亲水性。为了合成 PPLC 聚合物，将 LiTFSI (

2 wt %

) 和

CoPc (20 mM

加入 PP 水分散液（1 wt%）中，并在 1000 rpm 转速下剧烈搅拌 6 小时。然后，以 1500 rpm 的转速将均匀混合溶液旋涂在聚多巴胺涂层的 PDMS 薄膜上 60 秒，然后在

130^{\circ} C

下退火 15 分钟，形成 PPLC/PDMS 薄膜。

The patterned PPLC/PDMS films were obtained by two techniques. For photolithography, firstly, the PDMS film covered with a hollowed-out mask obtained by photolithography was soaked in dopamine hydrochloride solution for 24 h to obtain the patterned polydopamine-PDMS film, and then, the homogeneous mixture solution of PPLC was spin-coated on the surface of the PDMS film, forming the patterned PPLC/ PDMS film. As for inkjet printing, the patterned PPLC/PDMS
图案化的 PPLC/PDMS 薄膜是通过两种技术获得的。在光刻法中，首先将覆盖有光刻法得到的镂空掩模的PDMS薄膜在盐酸多巴胺溶液中浸泡24小时，得到图案化的聚多巴胺-PDMS薄膜，然后将PPLC的均匀混合溶液旋涂在PDMS薄膜表面，形成图案化的PPLC/PDMS薄膜。至于喷墨打印，图案化的 PPLC/PDMS
was printed on the polydopamine-PDMS film by an inkjet printer with PPLC solution as the conductive ink.
用喷墨打印机在聚多巴胺-PDMS 薄膜上打印，导电墨水为 PPLC 溶液。

Electrode fabrication for electrochemical detection
用于电化学检测的电极制造

To connect with the outer workstation, the two ends of the PPLC/PDMS electrode were connected with wires, and the joints were insulated by casting PDMS prepolymer which was then thermally cured at

80^{\circ} C

to ensure a chamber

(1.0 \times 0.5 \times 0.2

{cm}^{3}

) for holding solution for stretch-related electrochemical measurements. As for the bending-related and other electrochemical measurements, the PPLC/PDMS electrode was connected with a copper wire via carbon paste, and the joints were insulated to ensure a

0.5 \times 0.5 {cm}^{2}

active area

(1.0 \times 0.5 {cm}^{2}

active area for the amperometric

i - t

curve).
为了与外部工作站连接，PPLC/PDMS 电极的两端用导线连接，并通过浇注 PDMS 预聚物对连接处进行绝缘，然后在

80^{\circ} C

下进行热固化，以确保有一个

(1.0 \times 0.5 \times 0.2

{cm}^{3}

的腔室，用于容纳与拉伸有关的电化学测量溶液。至于与弯曲相关的电化学测量和其他电化学测量，PPLC/PDMS 电极通过碳浆与铜线连接，并对连接处进行绝缘处理，以确保

0.5 \times 0.5 {cm}^{2}

有效面积

(1.0 \times 0.5 {cm}^{2}

用于安培

i - t

曲线的有效面积）。

Flexibility and stretchability test
柔韧性和拉伸性测试

For the flexibility test, the PPLC/PDMS film was attached to a variety of cylinders with diverse outer curvature radii (0.5-12.5 mm ). As for the stretchability test, specific lengths of the film which corresponded to a set of strains were stretched by a linear sliding motor. The resistance of the film under different deformations was measured by using a multimeter.
在柔韧性测试中，PPLC/PDMS 薄膜被固定在各种外曲率半径（0.5-12.5 毫米）的圆柱体上。在拉伸性测试中，通过线性滑动马达拉伸与一组应变相对应的特定长度的薄膜。使用万用表测量薄膜在不同变形情况下的电阻。

Cell culture and imaging 细胞培养和成像

16HBECs were cultured using RPMI-1640 culture medium with FBS (

10 %

) and penicillin-streptomycin (1%) in a humidified incubator (

37^{\circ} C

and

5 % {CO}_{2}

). Before cell seeding, the PPLC/ PDMS electrode was thoroughly sterilized with ultraviolet exposure overnight. For electrochemical detection, 16HBECs (2

\times 10^{5}

cells per

{cm}^{2}

) were seeded on the PPLC/PDMS electrode, and a chamber was built around the PPLC layer utilizing PDMS prepolymer which was then thermally cured at

80^{\circ} C

to ensure a chamber

(1.0 \times 0.5 \times 0.2 {cm}^{3})

to store culture medium. After being cultured in an incubator for 20 h to allow cell adhesion, the culture medium was removed and the electrode was washed with sterile PBS for three times to remove loosely bonded cells. To assess the viability and released

H_{2} O_{2}

of 16HBECs cultured on the PPLC/PDMS electrode, fluorescent live/dead cell markers Calcein-AM (

2 μ g {mL}^{- 1}) / PI (3 μ g {mL}^{- 1})

and ROS fluorescent probe DCFH-DA (

10 μ M

) were used respectively.
16HBECs 采用含 FBS（

10 %

）和青霉素-链霉素（1%）的 RPMI-1640 培养基在加湿培养箱（

37^{\circ} C

和

5 % {CO}_{2}

）中培养。细胞播种前，PPLC/ PDMS 电极经紫外线照射一夜彻底消毒。为了进行电化学检测，在 PPLC/PDMS 电极上播种了 16HBECs （每个

{cm}^{2}

中有 2 个

\times 10^{5}

细胞），并利用 PDMS 预聚物在 PPLC 层周围建造了一个腔室，然后在

80^{\circ} C

下对其进行热固化，以确保有一个

(1.0 \times 0.5 \times 0.2 {cm}^{3})

腔室来储存培养基。在培养箱中培养 20 小时使细胞粘附后，移除培养基，用无菌 PBS 冲洗电极三次以去除松散粘附的细胞。为了评估在 PPLC/PDMS 电极上培养的 16HBECs 的活力和释放

H_{2} O_{2}

，分别使用了荧光活/死细胞标记物 Calcein-AM (

2 μ g {mL}^{- 1}) / PI (3 μ g {mL}^{- 1})

) 和 ROS 荧光探针 DCFH-DA (

10 μ M

) 。

Real-time monitoring of $H_{2} O_{2}$ release from stretched 16HBECs
实时监测拉伸 16HBEC 的 $H_{2} O_{2}$ 释放情况

To simultaneously achieve applying mechanical loading on cells and real-time monitoring of released

H_{2} O_{2}

, the PPLC/ PDMS electrodes bearing 16HBECs cultured well thereon were fixed on a linear sliding device with a hauling speed of 0.85 mm

s^{- 1}

and connected with the outer workstation by wires. Then, the stretchable sensors were stretched to different extents to simulate the normal state (10%) and bronchiectasis states (

20 %

and

30 %

) respectively. The concentrations of added DPI, catalase and L-NMMA were

0.5 mM, 60 kU mL

respectively. When monitoring

H_{2} O_{2}

release from 16HBECs stimulated by PMA, the final concentrations of PMA and catalase were

50 μ M

and

6 kU {mL}^{- 1}

respectively.
为了同时实现对细胞施加机械负荷和实时监测释放的

H_{2} O_{2}

，将带有16HBECs培养孔的PPLC/PDMS电极固定在牵引速度为0.85 mm的线性滑动装置

s^{- 1}

上，并通过导线与外部工作站连接。然后，将可拉伸传感器拉伸到不同程度，分别模拟正常状态（10%）和支气管扩张状态（

20 %

和

30 %

）。添加的 DPI、过氧化氢酶和 L-NMMA 的浓度分别为

0.5 mM, 60 kU mL

。在监测 PMA 刺激 16HBECs 释放

H_{2} O_{2}

时，PMA 和过氧化氢酶的最终浓度分别为

50 μ M

和

6 kU {mL}^{- 1}

。

Data availability 数据可用性

The raw image data generated and analysed that support the findings of this study are available from the corresponding author upon reasonable request. Source data are provided with this paper.
本研究结果所依据的原始图像数据的生成和分析，可向相应作者索取。本文随附原始数据。

Author contributions 作者供稿

Jing Yan and Yan-Ling Liu conceived and initiated the project. Jing Yan accomplished all the experiments and wrote the manuscript. Yu Qin, Wen-Ting Fan, Wen-Tao Wu and Li-Ping Yan helped to accomplish the cell experiments. Song-Wei Lv provided help in ink-jet printing. Yan-Ling Liu and Wei-Hua Huang supervised the project and revised the manuscript.
Jing Yan 和 Yan-Ling Liu 构思并发起了该项目。严静完成了所有实验并撰写了手稿。Yu Qin、Wen-Ting Fan、Wen-Tao Wu 和 Li-Ping Yan 协助完成了细胞实验。吕松伟为喷墨打印提供了帮助。刘艳玲和黄伟华指导了该项目并修改了手稿。

Conflicts of interest 利益冲突

There are no conflicts to declare.
没有需要声明的冲突。

Acknowledgements 致谢

We gratefully acknowledge financial support from the National Natural Science Foundation of China (Grants 22122408, 21804101, 21725504, and 21721005). We thank Prof. Zheng Liu from the Institute for Advanced Studies of Wuhan University for his help with the AFM characterization.
感谢国家自然科学基金的资助（22122408、21804101、21725504 和 21721005）。我们感谢武汉大学高等研究院的 Zheng Liu 教授在原子力显微镜表征方面提供的帮助。

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$^{a}$ College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China. E-mail: yanlingliu@whu.edu.cn; whhuang@whu.edu.cn $^{b}$ School of Pharmacy, Changzhou University, Changzhou 213164, China $†$ Electronic supplementary information (ESI) available. See DOI: 10.1039/d1sc04138j
$^{a}$ 武汉大学化学与分子科学学院，中国武汉 430072。电子邮件：yanlingliu@whu.edu.cn; whhuang@whu.edu.cn $^{b}$ 常州大学药学院，中国常州 213164 $†$ 电子补充信息（ESI）可用。参见 DOI: 10.1039/d1sc04138j

Plasticizer and catalyst co-functionalized PEDOT:PSS enables stretchable electrochemical sensing of living cells † † †\dagger增塑剂和催化剂共官能化 PEDOT:PSS 可实现活细胞的可拉伸电化学传感 † † †\dagger

Abstract 摘要

Introduction 导言

Results and discussion 结果和讨论

Fabrication and characterization of PPLC polymerPPLC 聚合物的制造和表征

Mechanical properties of the PPLC/PDMS electrodePPLC/PDMS 电极的机械性能

Electrochemical sensing performance of the PPLC/PDMS filmPPLC/PDMS 薄膜的电化学传感性能

Real-time monitoring of stretch-induced H 2 O 2 H 2 O 2 H_(2)O_(2)\mathrm{H}_{2} \mathrm{O}_{2} released from 16HBECs实时监测拉伸引起的 16HBECs H 2 O 2 H 2 O 2 H_(2)O_(2)\mathrm{H}_{2} \mathrm{O}_{2} 释放情况

Conclusions 结论

Experimental 实验性

Materials and methods 材料和方法

Fabrication of the PPLC/PDMS film制作 PPLC/PDMS 薄膜

Electrode fabrication for electrochemical detection用于电化学检测的电极制造

Flexibility and stretchability test柔韧性和拉伸性测试

Cell culture and imaging 细胞培养和成像

Real-time monitoring of H 2 O 2 H 2 O 2 H_(2)O_(2)\mathrm{H}_{2} \mathrm{O}_{2} release from stretched 16HBECs实时监测拉伸 16HBEC 的 H 2 O 2 H 2 O 2 H_(2)O_(2)\mathrm{H}_{2} \mathrm{O}_{2} 释放情况

Data availability 数据可用性

Author contributions 作者供稿

Conflicts of interest 利益冲突

Acknowledgements 致谢

References 参考资料

Plasticizer and catalyst co-functionalized PEDOT:PSS enables stretchable electrochemical sensing of living cells $†$
增塑剂和催化剂共官能化 PEDOT:PSS 可实现活细胞的可拉伸电化学传感 $†$

Fabrication and characterization of PPLC polymer
PPLC 聚合物的制造和表征

Mechanical properties of the PPLC/PDMS electrode
PPLC/PDMS 电极的机械性能

Electrochemical sensing performance of the PPLC/PDMS film
PPLC/PDMS 薄膜的电化学传感性能

Real-time monitoring of stretch-induced $H_{2} O_{2}$ released from 16HBECs
实时监测拉伸引起的 16HBECs $H_{2} O_{2}$ 释放情况

Fabrication of the PPLC/PDMS film
制作 PPLC/PDMS 薄膜

Electrode fabrication for electrochemical detection
用于电化学检测的电极制造

Flexibility and stretchability test
柔韧性和拉伸性测试

Real-time monitoring of $H_{2} O_{2}$ release from stretched 16HBECs
实时监测拉伸 16HBEC 的 $H_{2} O_{2}$ 释放情况