Li Meng-Jie, Wang Hai-Jun, Yuan Ruo, Chai Ya-Qin
Chongqing Engineering Laboratory of Nanomaterials & Sensor Technologies, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China; School of Civil Engineering and Architecture, Chongqing University of Science & Technology, Chongqing, 401331, PR China.
Chongqing Engineering Laboratory of Nanomaterials & Sensor Technologies, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Biosens Bioelectron. 2021 Jun 1;181:113162. doi: 10.1016/j.bios.2021.113162. Epub 2021 Mar 13.
Herein, a sensitive label-free photoelectrochemical (PEC) aptasensor was constructed for C-reactive protein (CRP) analysis based on a novel and efficient poly{4,8-bis[5-(2-ethylhexyl) thiophen-2-yl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]-thiophene-4,6-diyl} (PTB7-Th)/HO system with unexpected photoelectric performance. The proposed PTB7-Th/HO system without any sensitizer could surmount defect of the poor photoelectric conversion efficiency of PTB7-Th, leading to the unexpected 10-fold photocurrent enhancement compared to the common PTB7-Th/PBS system. The strong enhancement effect might originate from the special function of hydrogen peroxide (HO) towards PTB7-Th. On the one hand, HO as electron acceptor could continuously capture photogenerated electrons located at acceptor part of PTB7-Th, which would visibly improve the charge separation efficiency of PTB7-Th and the electron-receiving property of electrolyte solution, thus leading to the obviously enhanced photoelectric conversion efficiency (PCE). More importantly, HO as oxidant could oxidize PTB7-Th to obtain oxidation product of PTB7-Th (OPP) with carbonyl group and carboxyl group, and the electron cloud density in donor part of the OPP was higher than that of PTB7-Th, therefrom producing the stronger electron-donating property and higher photoelectrochemical (PEC) reaction efficiency. As a proof of concept, the proposed PTB7-Th/HO system was successfully applied in the construction of a label-free PEC aptasensor for sensitive analysis of CRP, which performed a wide detection range from 1 pM to 1000 nM with a low detection limit of 0.33 pM. This study demonstrated a novel approach to the rational design of photoelectric conversion system with high PEC performance and provided an inspired tack for the construction of high-efficiency photoelectric devices.
在此，基于一种具有意外光电性能的新型高效聚{4,8-双[5-(2-乙基己基)噻吩-2-基]苯并[1,2-b:4,5-b']二噻吩-2,6-二基-alt-3-氟-2-[(2-乙基己基)羰基]噻吩并[3,4-b]噻吩-4,6-二基}(PTB7-Th)/HO体系，构建了一种用于C反应蛋白(CRP)分析的灵敏无标记光电化学(PEC)适配体传感器。所提出的PTB7-Th/HO体系无需任何敏化剂，可克服PTB7-Th光电转换效率低的缺陷，与普通的PTB7-Th/PBS体系相比，光电流意外增强了10倍。这种强烈的增强效应可能源于过氧化氢(HO)对PTB7-Th的特殊作用。一方面，HO作为电子受体可以持续捕获位于PTB7-Th受体部分的光生电子，这将显著提高PTB7-Th的电荷分离效率和电解质溶液的电子接受性能，从而导致光电转换效率(PCE)明显提高。更重要的是，HO作为氧化剂可以氧化PTB7-Th以获得具有羰基和羧基的PTB7-Th氧化产物(OPP)，并且OPP供体部分的电子云密度高于PTB7-Th，由此产生更强的供电子性能和更高的光电化学(PEC)反应效率。作为概念验证，所提出的PTB7-Th/HO体系成功应用于构建用于CRP灵敏分析的无标记PEC适配体传感器，其检测范围宽，从1 pM到1000 nM，检测限低至0.33 pM。本研究展示了一种合理设计具有高PEC性能的光电转换系统的新方法，并为构建高效光电器件提供了启发。
