A simple approach for protein covalent grafting on conducting polymer films

Covalent immobilization of biomolecules, such as proteins, on conducting polymer films is critical to organic bioelectronics to create tailored interfaces with biological systems. In this study, we propose a simple approach to graft proteins on films of the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS). PEDOT: PSS is a biocompatible and easy to process conducting polymer, widely used in bioelectronics. However, it does not possess any chemical reactive groups available for protein grafting. By mixing a commercial PEDOT: PSS suspension with the modified biopolymer carboxymethylated dextran (CMD), we obtained films displaying carboxyl (-COOH) groups allowing for covalent grafting of proteins via amide bonds, without any further functionalization step. By fine-tuning the concentration of CMD as well as those of a conductivity enhancer (glycerol) and a crosslinking agent (glycidoxypropyltrimethoxysilane, GOPS) in the film processing mixture, we were able to produce COOH-functionalized PEDOT: PSS films displaying excellent electrical conductivity and high stability in an aqueous environment.

将生物分子（如蛋白质）共价固定在导电聚合物薄膜上对于有机生物电子学至关重要，以便创建与生物系统适配的界面。在这项研究中，我们提出了一种简单的方法，将蛋白质接枝到掺杂聚苯乙烯磺酸盐（PEDOT:PSS）的导电聚合物聚（3,4 - 乙烯二氧噻吩）薄膜上。PEDOT:PSS是一种生物相容性好且易于加工的导电聚合物，广泛应用于生物电子学领域。然而，它不具备任何可用于蛋白质接枝的化学反应基团。通过将市售的PEDOT:PSS悬浮液与改性生物聚合物羧甲基化葡聚糖（CMD）混合，我们得到了带有羧基（-COOH）的薄膜，这些羧基可通过酰胺键实现蛋白质的共价接枝，无需任何进一步的功能化步骤。通过精细调整薄膜加工混合物中CMD的浓度以及导电增强剂（甘油）和交联剂（环氧丙氧基丙基三甲氧基硅烷，GOPS）的浓度，我们能够制备出在水环境中具有优异导电性和高稳定性的羧基功能化PEDOT:PSS薄膜。