基于CDs@SiNWs的光电化学免疫传感器构建及性能研究

采用金属辅助化学蚀刻法制备高定向硅纳米线阵列(silicon nanowire arrays, SiNWs),结合碳点(carbon dots,CDs)改性制备了一种新型无标记光电免疫传感器,用于心肌肌钙蛋白I(cardiac troponin I, cTnI)的检测。N型SiNWs作为光阳极,可获得强的光电信号基底响应。采用旋涂法将CDs负载于SiNWs表面,可以提高SiNWs对可见光的吸收能力,促进光生载流子分离,从而提高SiNWs的光电性能;同时,CDs为抗体连接提供了羧基活性位点。基于CDs@SiNWs的光电免疫传感器对cTnI的检测具有良好的线性范围(0.005～5.000 ng/mL)和较低的检出限(3.79 pg/mL)。所设计的光电化学（photoelectrochemical, PEC）免疫传感器具有良好的灵敏度、稳定性和重复性。该电极可实现无标签检测,为实现cTnI的即时检测提供了新的途径。

Construction and performance of photoelectrochemical immunosensor based on CDs@SiNWs

A novel label-free photoimmunosensor was prepared by metal-assisted chemical etching of highly oriented silicon nanowire arrays (SiNWs) combined with carbon dots (CDs) modification for the detection of cardiac troponin I (cTnI). N-type SiNWs were used as photoanodes to obtain a strong photoelectric signal response. CDs are loaded on the surface of SiNWs by the spin-coating method. CDs can improve the photoelectric performance of SiNWs by enhancing the absorption of visible light and promoting the separation of photogenerated carriers; meanwhile, CDs provide the carboxyl active site for antibody attachment. The CDs@SiNWs-based immunosensor has a good linear range (0.005-5.000 ng/mL) and a low detection limit (3.79 pg/mL) for the detection of cTnI. The designed photoelectrochemical (PEC) immunosensor has good sensitivity, stability, and reproducibility. The electrode enables label-free detection and provides a new way to achieve immediate detection of cTnI.