Table_1_Organic Electrochemical Transistors/SERS-Active Hybrid Biosensors Featuring Gold Nanoparticles Immobilized on Thiol-Functionalized PEDOT Films.doc

In this study we immobilized gold nanoparticles (AuNPs) onto thiol-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) films as bioelectronic interfaces (BEIs) to be integrated into organic electrochemical transistors (OECTs) for effective detection of dopamine (DA) and also as surface-enhanced Raman scattering (SERS)—active substrates for the selective detection of p-cresol (PC) in the presence of multiple interferers. This novel PEDOT-based BEI device platform combined (i) an underlying layer of polystyrenesulfonate-doped PEDOT (PEDOT:PSS), which greatly enhanced the transconductance and sensitivity of OECTs for electrochemical sensing of DA in the presence of other ascorbic acid and uric acid metabolites, as well as amperometric response toward DA with a detection limit (S/N = 3) of 37 nM in the linear range from 50 nM to 100 μM; with (ii) a top interfacial layer of AuNP-immobilized three-dimensional (3D) thiol-functionalized PEDOT, which not only improved the performance of OECTs for detecting DA, due to the signal amplification effect of the AuNPs with high catalytic activity, but also enabled downstream analysis (SERS detection) of PC on the same chip. We demonstrate that PEDOT-based 3D OECT devices decorated with a high-density of AuNPs can display new versatility for the design of next-generation biosensors for point-of-care diagnostics.

本研究将金纳米颗粒（AuNPs）固定于巯基功能化聚(3,4-乙撑二氧噻吩)（PEDOT）薄膜上，制备得到生物电子界面（BEIs）：一方面将其集成至有机电化学晶体管（OECTs）中以实现多巴胺（DA）的高效检测，另一方面将其作为表面增强拉曼散射（SERS）活性基底，用于在多种干扰物共存下选择性检测对甲酚（PC）。这款基于PEDOT的新型BEI器件平台包含两大核心模块：(i) 聚苯乙烯磺酸盐掺杂PEDOT（PEDOT:PSS）底层，该层不仅显著提升了OECTs在抗坏血酸、尿酸等代谢物共存体系中电化学检测DA的跨导与灵敏度，同时实现了对DA的安培响应，在50 nM至100 μM的线性范围内，检测限（信噪比S/N=3）可达37 nM；(ii) 负载金纳米颗粒的三维巯基功能化PEDOT顶层界面，该界面不仅借助高催化活性AuNPs的信号放大效应优化了OECTs检测DA的性能，还可实现同一芯片上PC的后续SERS检测分析。本研究证实，修饰有高密度AuNPs的PEDOT基三维OECT器件，可为面向即时诊断的下一代生物传感器设计提供全新的多功能性。