Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden.
Center of Excellence for Trace Analysis and Biosensor, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
ACS Appl Mater Interfaces. 2020 Sep 2;12(35):39841-39849. doi: 10.1021/acsami.0c10270. Epub 2020 Aug 20.
Modulation of chemical functional groups on conducting polymers (CPs) provides an effective way to tailor the physicochemical properties and electrochemical performance of CPs, as well as serves as a functional interface for stable integration of CPs with biomolecules for organic bioelectronics (OBEs). Herein, we introduced a facile approach to modulate the carboxylate functional groups on the PEDOT interface through a systematic evaluation on the effect of a series of carboxylate-containing molecules as counterion dopant integrated into the PEDOT backbone, including acetate as monocarboxylate (mono-COO), malate as dicarboxylate (di-COO), citrate as tricarboxylate (tri-COO), and poly(acrylamide--acrylate) as polycarboxylate (poly-COO) bearing different amounts of molecular carboxylate moieties to create tunable PEDOT:COO interfaces with improved polymerization efficiency. We demonstrated the modulation of PEDOT:COO interfaces with various granulated morphologies from 0.33 to 0.11 μm, tunable surface carboxylate densities from 0.56 to 3.6 μM cm, and with improved electrochemical kinetics and cycling stability. We further demonstrated the effective and stable coupling of an enzyme model lactate dehydrogenase (LDH) with the optimized PEDOT:poly-COO interface via simple covalent chemistry to develop biofunctionalized PEDOT (Bio-PEDOT) as a lactate biosensor. The biosensing mechanism is driven by a sequential bioelectrochemical signal transduction between the bio-organic LDH and organic PEDOT toward the concept of all-polymer-based OBEs with a high sensitivity of 8.38 μA mM cm and good reproducibility. Moreover, we utilized the LDH-PEDOT biosensor for the detection of lactate in spiked serum samples with a high recovery value of 91-96% and relatively small RSD in the range of 2.1-3.1%. Our findings provide a new insight into the design and optimization of functional CPs, leading to the development of new OBEs for sensing, biosensing, bioengineering, and biofuel cell applications.
在导电聚合物（CPs）上调节化学官能团为调整 CPs 的物理化学性质和电化学性能提供了一种有效方法，同时也为 CPs 与生物分子的稳定集成提供了一个功能界面，以用于有机生物电子学（OBEs）。在此，我们通过系统评估一系列含羧酸盐分子作为共离子掺杂剂整合到 PEDOT 主链中对 PEDOT 界面上的羧酸盐官能团的影响，引入了一种调节 PEDOT 界面上的羧酸盐功能的简便方法，这些共离子掺杂剂包括作为单羧酸盐（单-COO）的醋酸盐、作为二羧酸盐（二-COO）的苹果酸盐、作为三羧酸盐（三-COO）的柠檬酸盐以及带有不同数量的分子羧酸盐部分的聚（丙烯酰胺-丙烯酸酯）作为多羧酸盐（多-COO），以创建具有改进的聚合效率的可调谐 PEDOT：COO 界面。我们展示了具有从 0.33 到 0.11 μm 的各种粒状形态、从 0.56 到 3.6 μM cm 的可调表面羧酸盐密度以及具有改进的电化学动力学和循环稳定性的 PEDOT：COO 界面的调节。我们进一步通过简单的共价化学将酶模型乳酸脱氢酶（LDH）与优化的 PEDOT：poly-COO 界面有效且稳定地偶联，以开发作为乳酸生物传感器的功能化 PEDOT（Bio-PEDOT）。生物传感机制是由生物有机 LDH 和有机 PEDOT 之间的顺序生物电化学信号转导驱动的，朝着具有高灵敏度 8.38 μA mM cm 和良好重现性的全聚合物 OBEs 的概念发展。此外，我们利用 LDH-PEDOT 生物传感器检测了含有人血清样品中的乳酸，回收率值为 91-96%，相对标准偏差（RSD）在 2.1-3.1%范围内较小。我们的研究结果为功能 CP 的设计和优化提供了新的见解，为用于传感、生物传感、生物工程和生物燃料电池应用的新型 OBEs 的发展提供了新的思路。
