Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Anal Chem. 2023 Aug 22;95(33):12383-12390. doi: 10.1021/acs.analchem.3c01935. Epub 2023 Aug 10.
Herein, an ultrasensitive photocathodic biosensor was fabricated based on CuO/PTB7-Th/PDA photoactive materials with high photocarrier separation efficiency for the detection of microRNA-375-3p. Impressively, the photocathodic signal of the CuO material was significantly enhanced by using PTB7-Th as an energy level-matching photoactive material to enhance the bulk charge separation and ,-bis (2-(trimethylammoniumiodide) propylene) perylene-3,4,9,10-tetracarboxydiimide (PDA) as an interfacial charge transfer mediator to efficiently suppress charge recombination at the photoelectrode/electrolyte interface. Compared with the pristine CuO as a photocathode, the obtained CuO/PTB7-Th/PDA exhibited a 17 times higher photocathodic signal. As a proof of concept, a PEC biosensor was fabricated by using CuO/PTB7-Th/PDA as a photoactive material and a target-triggered 3D DNA walker integrated with the dumbbell hybridization chain reaction (DHCR) as a signal amplifier to achieve the sensitive detection of microRNA-375-3p with a detection limit of 0.3 fM. This work provided a method to increase the photocurrent signal and the sensitivity of PEC-sensing platforms for the detection of biomarkers and disease diagnosis.
本文构建了一种基于具有高光载分离效率的 CuO/PTB7-Th/PDA 光活性材料的超灵敏光阴极生物传感器，用于检测 microRNA-375-3p。令人印象深刻的是，通过使用 PTB7-Th 作为能级匹配的光活性材料来增强体相电荷分离，以及 - 双（2-（三甲基碘化铵）丙烯）苝-3,4,9,10-四羧酸二亚胺（PDA）作为界面电荷转移介质，显著增强了 CuO 材料的光阴极信号，从而有效地抑制了光电极/电解质界面处的电荷复合。与原始的 CuO 作为光阴极相比，所获得的 CuO/PTB7-Th/PDA 表现出 17 倍更高的光阴极信号。作为概念验证，制备了一种 PEC 生物传感器，该传感器使用 CuO/PTB7-Th/PDA 作为光活性材料，并将目标触发的 3D DNA walker 与哑铃形杂交链式反应（DHCR）集成作为信号放大器，以实现对 microRNA-375-3p 的灵敏检测，检测限低至 0.3 fM。这项工作为提高光电流信号和 PEC 传感平台的灵敏度以用于生物标志物检测和疾病诊断提供了一种方法。
