Institute for Advanced Interdisciplinary Research, University of Jinan, Jinan, 250022, PR China.
Institute of Materia Medica, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, PR China.
Anal Chim Acta. 2022 Sep 15;1226:340265. doi: 10.1016/j.aca.2022.340265. Epub 2022 Aug 17.
Herein, a high-sensitivity photoelectrochemical (PEC) biosensor was developed based on CdS quantum dots (QDs) sensitized porous hexagonal boron nitride (h-BN) nanosheets (NSs) and the multiple sites tripodal DNA walker (TDW) formed by catalytic hairpin assembly (CHA). Noticeably, the porous structure of h-BN NSs gives it a lasting gift of large specific surface areas and extensive active reaction sites, which makes it possible to be employed as photoelectric substrate material. The h-BN/CdS QDs composite material promotes the transmission of photogenerated electrons and holes, the outstanding photoelectric conversion efficiency. Meanwhile, the CHA-formed TDWs triggered by miRNA-141 moved on track strand-functionalized electrode, so that a large number of alkaline phosphatase (ALP) was immobilized on the electrode surface and further in situ catalyzed ascorbic acid 2-phosphate (AAP) to produce ascorbic acid (AA) as the electron donor. As the result of the decisive influence of electron donor on PEC biosensor, the sensitive detection of miRNA-141 was realized. The proposed PEC biosensor displayed an excellent linear relationship ranging from 1 fM to 100 nM with a detection limit of 0.73 fM, providing a powerful strategy for early clinical diagnosis and biomedical research.
本文基于 CdS 量子点（QDs）敏化多孔六方氮化硼（h-BN）纳米片（NSs）和由催化发夹组装（CHA）形成的多位点三足 DNA walker（TDW），开发了一种高灵敏度光电化学（PEC）生物传感器。值得注意的是，h-BN NSs 的多孔结构赋予其持久的大比表面积和广泛的活性反应位点的礼物，使其有可能被用作光电基板材料。h-BN/CdS QDs 复合材料促进光生电子和空穴的传输，具有出色的光电转换效率。同时，miRNA-141 触发的 CHA 形成的 TDW 在轨道链功能化电极上移动，从而在电极表面固定大量碱性磷酸酶（ALP），并进一步原位催化抗坏血酸 2-磷酸（AAP）产生作为电子供体的抗坏血酸（AA）。由于电子供体对 PEC 生物传感器的决定性影响，实现了对 miRNA-141 的灵敏检测。所提出的 PEC 生物传感器在 1 fM 至 100 nM 的范围内表现出优异的线性关系，检测限为 0.73 fM，为早期临床诊断和生物医学研究提供了强大的策略。
