Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
Biosens Bioelectron. 2022 Dec 15;218:114759. doi: 10.1016/j.bios.2022.114759. Epub 2022 Sep 28.
Efficient signal amplification using light irradiation in electrochemistry-based sensing attracts growing interest; however, the modulation of electrochemical and photoelectrochemical behaviors of bifunctional probes remains challenging for the better analytical performance. Here, we found that the bifunctional probe methylene blue (MB) under irradiation followed two routes, i.e., photoelectrochemistry (PEC)-driven and electrochemistry (EC)-driven route, while plasmon-modulated competition between PEC-driven and EC-driven routes efficiently enhanced the analytical performance of aptasensor. Ferrocene-labeled aptamer (Fc-apt) was applied to tune the interaction between MB labeled complementary DNA (MB-cDNA) and plasmonic gold nanoparticles (AuNPs). Under visible light illumination, the aptasensor output a weak current of MB (I) for the depressed EC-driven redox. The binding of Fc-apt with target led to its stripping from electrode and released MB-cDNA to approach AuNPs, and an increase in I was observed due to the synergy of the depressed PEC-driven redox while the restored EC-driven redox. In this way, the amplified response for target could be obtained by depressing background signal while enlarging response signal of I under visible light. Consequently, the developed model ratiometric aptasensor offered a higher sensitivity for the determination of aflatoxin B1. Our observation should be favorable to shed light on photo-induced electrochemical mechanism, and the proposed amplification strategy is valuable for the construction of efficient sensors.
利用电化学传感中的光照射实现高效信号放大引起了越来越多的关注；然而，对于更好的分析性能，双功能探针的电化学和光电化学行为的调制仍然具有挑战性。在这里，我们发现，受光照射的双功能探针亚甲蓝（MB）遵循两条途径，即光电化学（PEC）驱动和电化学（EC）驱动途径，而等离子体调制的 PEC 驱动和 EC 驱动途径之间的竞争有效地增强了适体传感器的分析性能。 标记有二茂铁的适体（Fc-apt）用于调节 MB 标记互补 DNA（MB-cDNA）与等离子体金纳米粒子（AuNPs）之间的相互作用。在可见光照射下，适体传感器输出 MB 的弱电流（I），这是由于 EC 驱动的氧化还原被抑制。Fc-apt 与靶标结合导致其从电极上脱附，并释放 MB-cDNA 接近 AuNPs，并且由于抑制的 PEC 驱动的氧化还原同时恢复的 EC 驱动的氧化还原的协同作用，观察到 I 的增加。通过这种方式，可以通过抑制背景信号并放大 I 的响应信号来获得针对目标的放大响应。因此，所开发的比率型适体传感器为黄曲霉毒素 B1 的测定提供了更高的灵敏度。我们的观察结果应该有利于阐明光诱导电化学机制，并且所提出的放大策略对于构建高效传感器具有价值。
