A sensitive electrochemiluminescence immunosensor for the detection of PSA based on CdWS nanocrystals and Ag+@UIO-66-NH2 as a novel coreaction accelerator

Abstract

In this work, an effective sandwich electrochemiluminescence (ECL) immunosensing scheme was successfully constructed for the determination of prostate specific antigen (PSA). Specifically, self-prepared dual-stabilizers-capped CdWS nanocrystals (NCs) was integrated onto Ag+@UIO-66-NH2 which is a novel coreaction accelerator for improving ECL intensity of the CdWS/S2O82− system, to create a Ag+@UIO-66-NH2@CdWS ECL nanoprobes for increasing the analysis sensitivity efficiently. Reduced graphene oxide (rGO) and Au NPs were modified on the surface of GCE to set up a stable sensitive sensing area, on which PSA capture antibody (Ab1) was immobilized to capture PSA via antigen-antibody immunoreaction. Then Ag+@UIO-66-NH2@CdWS labeled antibody (Ab2) was used as signal probe. Under the optimal conditions, the ECL intensity presented an excellent linear relationship with the logarithm of PSA concentration from 0.0001 to 10 ng mL−1, with a low detection limit of 0.038 pg mL−1. This indicated that the designed ECL biosensor is valuable, innovative, and wide linearity to the detection of PSA, which provides a worthy method in clinical diagnosis. More importantly, this work provided CdWS NCs luminophor and Ag+@UIO-66-NH2 coreaction accelerator, which improve the sensitivity of goal analysis in the field of ECL biosensor.