Yang Ruiying, Jiang Guihua, Liu Jie, Wang Yilin, Jian Ningge, He Leiliang, Liu Li'e, Qu Lingbo, Wu Yongjun
College of Public Health, Zhengzhou University, Zhengzhou, 450001, China.
College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, China.
Anal Chim Acta. 2021 Apr 8;1153:338283. doi: 10.1016/j.aca.2021.338283. Epub 2021 Feb 7.
An ultrasensitive and selective photoelectrochemical (PEC) biosensor with cathodic background signal was developed for the detection of carcinoembryonic antigen (CEA) based on innovative plasmonic TiO@Au nanoparticles//CdS quantum dots (TiO@Au NPs//CdS QDs) photocurrent-direction switching system, coupling with hybridization chain reaction (HCR) for the signal amplification. Firstly, innovative TiO@Au NPs were successfully fabricated through in situ ascorbic acid-reduction of Au NPs dispersed on TiO surface, and TiO@Au NPs as the photoactive material showed a cathodic background signal. When target CEA existed, a sandwich-type reaction was performed in capture CEA aptamer-modified TiO@Au NPs and trigger CEA aptamer. Interestingly, after HCR triggered by target CEA, a mass of CdS QDs were introduced into the biosensing platform, resulting in the formation of TiO@Au NPs//CdS QDs system, along with the switch of photocurrents from cathodic to anodic. The obtained remarkable anodic photocurrent was depended on the localized surface plasmon resonance (LSPR) effect of Au between TiO and CdS. Under the optimal conditions, plasmonic TiO@Au NPs//CdS QDs photocurrent-direction switching PEC biosensing platform with cathodic background signal exhibited ultrasensitive for the determination of CEA with a low limit of detection of 18.9 fg/mL. Importantly, the proposed PEC biosensor can eliminate the interferences of the initial photocurrent and background signal, and has high-efficiency anti-interference ability, satisfactory stability and excellent reproducibility, which may have great potentials in bioanalysis and disease diagnosis.
基于创新的等离子体TiO@Au纳米粒子//硫化镉量子点（TiO@Au NPs//CdS QDs）光电流方向切换系统，并结合杂交链式反应（HCR）进行信号放大，开发了一种具有阴极背景信号的超灵敏且选择性的光电化学（PEC）生物传感器，用于检测癌胚抗原（CEA）。首先，通过原位抗坏血酸还原分散在TiO表面的Au NPs成功制备了创新的TiO@Au NPs，并且作为光活性材料的TiO@Au NPs显示出阴极背景信号。当目标CEA存在时，在捕获CEA适配体修饰的TiO@Au NPs和触发CEA适配体之间进行夹心型反应。有趣的是，在目标CEA触发HCR后，大量的CdS QDs被引入生物传感平台，导致形成TiO@Au NPs//CdS QDs系统，同时光电流从阴极切换到阳极。所获得的显著阳极光电流取决于TiO和CdS之间Au的局部表面等离子体共振（LSPR）效应。在最佳条件下，具有阴极背景信号的等离子体TiO@Au NPs//CdS QDs光电流方向切换PEC生物传感平台对CEA的测定表现出超灵敏性，检测下限低至18.9 fg/mL。重要的是，所提出的PEC生物传感器可以消除初始光电流和背景信号的干扰，具有高效的抗干扰能力、令人满意的稳定性和出色的重现性，这在生物分析和疾病诊断中可能具有巨大潜力。
