A Label-Free Electrochemical Immunosensor Based on AuAgPt NDs Functionalized MoO2 Nanosheets for Highly Sensitive Detection of AFP

In this work, a label-free electrochemical immunosensor was structured for detecting alpha fetal protein (AFP) effectively. The proposed electrochemical immunosensor was structured by gold silver platinum nanodendrites loaded on amino-functionalized MoO 2 nanosheets (AuAgPt NDs/NH 2 -MoO 2 NSs). The AuAgPt NDs with rich dendrite structure provided abundant specific surface area for effective capture antibody. MoO 2 possessed the satisfactory catalytic ability in terms of H 2 O 2 reduction and charge transfer capacity. AuAgPt NDs possessed favourable catalytic performance to H 2 O 2 reduction. Therefore, the prepared AuAgPt NDs/NH 2 -MoO 2 NSs was better than AuAgPt NDs and NH 2 -MoO 2 NSs in H 2 O 2 reduction on account of a synergistic effect. The constructed electrochemical immunosensor possessed a satisfying detection limit of 3.3 fg ml −1 and a broad detection range which was from 10 fg ml −1 to 100 ng ml −1 (S/N = 3) for the AFP detection under optimal conditions. The constructed electrochemical immunosensor possessed favourable detection performance in sensitivity, stability, selectivity and reproducibility, which indicated that it possessed a practical application in the aspect of clinical detection.