Dual-type responsive electrochemical biosensor for the detection of alpha 2,6-sialylated glycans based on AuNRs-SA coupled with c-SWCNHs/S-PtNC nanocomposites signal amplification

摘要

In this study, a dual-type responsive electrochemical biosensor was developed for the quantitative detection of alpha 2,6-sialylated glycans (alpha 2,6-sial-Gs), a potential biomarker of tumors. The gold nanorods (AuNRs), which exhibited great specific surface area, as well as good biocompatibility, was synthesized by the way of seed growth method. Furthermore, a biotin-streptavidin (biotin-SA) system was introduced to improve the immunoreaction efficiency. Accordingly, a label-free biosensor was fabricated based on AuNits-SA for the quick detection of alpha 2,6-sial-Gs by recording the signal of differential pulse voltammetry (DPV). Furthermore, to expand the ultrasensitive detection of alpha 2,6-sial-Gs, a carboxylated single-walled carbon nanohoms/sulfur-doped platinum nanocluster (c-SWCNHs/S-PtNC) was synthesized for the first time as a novel signal label, which showed an excellent catalytic performance. The usage of c-SWCNHs/S-PtNC could significantly amplify the electrochemical signal recorded by the amperometric i-t curve. Herein, a sandwich type biosensor was constructed by combining the AuNRs-SA on the electrode and c-SWCNHs/S-PtNC (signal amplifier). The label-free biosensor possessed a linear range from 5 ng mL(-1) to 5 mu g mL(-1) with a detection limit of 0.50 ng mL(-1), and the sandwich-type biosensor possessed a wide linear range from 1 mu g mL(-1) to 100 ng mL(-1) with a detection limit of 0.69 mu g mL(-1). Furthermore, the biosensor exhibited excellent recovery and stability, indicating its potential for use in actual samples.