Zhou Yuecheng, Liu Erica, Österholm Anna M, Jones Austin L, Sun Pengwei, Yang Yang, Tsai Ching-Ting, Zaluska Tomasz, Zhang Wei, Müller Holger, Reynolds John R, Cui Bianxiao
Department of Chemistry, Stanford University, Stanford, CA, USA.
Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
Nat Commun. 2025 Jul 23;16(1):6776. doi: 10.1038/s41467-025-61708-y.
Dioxythiophene-based polymers are electrochromic, effectively converting electric potentials into optical signals through voltage-dependent changes in absorption. The electrochromic property of these π-conjugated polymers can be harnessed to transform miniscule bioelectric signals, such as neuronal action potentials, into optical readouts. To enhance sensitivity, we investigated the impact of backbone and side-chain chemistry of dioxythiophene-based polymers. Among them, P(OE3)-E, a copolymer of oligoether-functionalized 3,4-propylenedioxythiophene with unsubstituted 3,4-ethylenedioxythiophene, exhibits the highest electrochromic sensitivity for optical bioelectric potential detection. A crucial factor in optimizing detection sensitivity is aligning the electric potential that triggers the sharpest optical transition in electrochromic polymers with the redox potential of the biological environment. Using P(OE3)-E thin films, we reliably detected field potentials from isolated rat hearts, extracellular action potentials of stem cell-derived cardiomyocytes, and spontaneous action potentials of dissociated rat hippocampal neurons. Our results achieved a detection sensitivity of ~3.3 µV with sub-millisecond temporal resolution, matching that of traditional electrode-based recordings while eliminating the constraints of electrode patterning or placement. This work highlights the significant potential of π-conjugated polymers for advancing bioelectric detection technologies.
基于二氧噻吩的聚合物具有电致变色特性，能够通过吸收随电压变化的特性有效地将电势转换为光信号。这些π共轭聚合物的电致变色特性可用于将微小的生物电信号，如神经元动作电位，转换为光学读数。为了提高灵敏度，我们研究了基于二氧噻吩的聚合物的主链和侧链化学结构的影响。其中，P(OE3)-E，一种由寡醚功能化的3,4-丙撑二氧噻吩与未取代的3,4-乙撑二氧噻吩的共聚物，在光学生物电势检测中表现出最高的电致变色灵敏度。优化检测灵敏度的一个关键因素是使电致变色聚合物中引发最急剧光学转变的电势与生物环境的氧化还原电势相匹配。使用P(OE3)-E薄膜，我们可靠地检测了来自离体大鼠心脏的场电位、干细胞衍生心肌细胞的细胞外动作电位以及离体大鼠海马神经元的自发动作电位。我们的结果实现了约3.3 μV的检测灵敏度，具有亚毫秒级的时间分辨率，与传统基于电极的记录相当，同时消除了电极图案化或放置的限制。这项工作突出了π共轭聚合物在推进生物电检测技术方面的巨大潜力。
