Ai Simin, Liu Yaling, Chai Yaqin, Yuan Ruo, Liu Hongyan
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
Biosens Bioelectron. 2022 Jul 1;207:114176. doi: 10.1016/j.bios.2022.114176. Epub 2022 Mar 9.
The sensitivity of cathodic photoelectrochemical (PEC) biosensor is mainly limited by the weak photocurrent response of p-type semiconductors due to the intrinsic weak hole conduction and severe charge recombination. Herein, we developed an antenna-like strategy that can amplify 10-fold of the cathodic photocurrent without using of p-type semiconductor. Specifically, poly (3,4-ethyl-enedioxythiophene) (PEDOT) was used as photocathode to improve the migration of photo-generated electrons (e) from the n-type S doped-BiWO (BiWOS) photoanode through the external circuit and therefore an amplified cathodic photocurrent can be obtained toward such an antenna-like strategy. We further demonstrated that the antenna-like effect is originated from the super electrical conductivity of PEDOT photocathode and the facilitated charge separation of BiWOS photoanode by S doping. As a proof of concept, a self-powered dual-photoelectrode cathodic PEC biosensor driven by visible light was fabricated for microRNA-141 detection. Importantly, the biological recognition occurred at the photocathode could advance the anti-interference capability of the biosensor and show outstanding performance for microRNA-141 detection with a low limit of detection (LOD) of 0.3 fM. The antenna-like strategy offers a new method to amplify the cathodic photocurrent for sensitively PEC analysis.
阴极光电化学（PEC）生物传感器的灵敏度主要受限于p型半导体的光电流响应较弱，这是由于其固有的空穴传导较弱以及严重的电荷复合所致。在此，我们开发了一种类似天线的策略，该策略无需使用p型半导体即可将阴极光电流放大10倍。具体而言，聚（3,4-乙撑二氧噻吩）（PEDOT）被用作光阴极，以改善光生电子（e）从n型S掺杂的BiWO（BiWOS）光阳极通过外部电路的迁移，因此，针对这种类似天线的策略可以获得放大的阴极光电流。我们进一步证明，类似天线的效应源自PEDOT光阴极的超导电性以及S掺杂对BiWOS光阳极电荷分离的促进作用。作为概念验证，制备了一种由可见光驱动的自供电双光电极阴极PEC生物传感器用于检测microRNA-141。重要的是，在光阴极发生的生物识别可以提高生物传感器的抗干扰能力，并在检测microRNA-141时表现出出色的性能，检测下限低至0.3 fM。这种类似天线的策略为放大阴极光电流以进行灵敏的PEC分析提供了一种新方法。
