Label-free electrochemiluminescent immunosensor for prostate specific antigen ultrasensitive detection based on novel luminophore Ag3PO4 decorated GO

A label-free electrochemiluminescence (ECL) sensor having high sensitivity was operated for detection of prostate specific antigen (PSA) by using silver/silver orthophosphate/graphene oxide composites (Ag/Ag 3 PO 4 /GO) as antibody carriers and sensing platform. Firstly, nanoparticles of Ag 3 PO 4 were employed as luminescent materials for solid-state ECL detection and to propose possible luminescence route in this study. GO, having the ultrahigh specific surface area and superior conductivity, was utilized as a loading matrix for nanoparticles of Ag 3 PO 4. It was employed not only to contribute for the enhancement of electrons transfer for the whole ECL system, but also further improvement of the sensitivity of the immunosensor. Given that the spectacular biocompatibility of silver nanoparticles (Ag NPs) was used to immobilize PSA antibody (anti-PSA) via the covalent coupling between silver and amino group, to improve immunosensor sensitivity. The proposed sensing platform presented tremendous cathodic ECL performance and better response to the PSA. Under optimized experimental conditions, the proposed immunosensor displayed a calibration range of 0.001–80   ng/mL and low detection limit of 0.3   pg/mL (S/N   =   3) for PSA determination. Featuring encouraging selectivity, repeatability, and stability, the fabricated Ag/Ag 3 PO 4 /GO is anticipated to glare novel ECL biosensor platform for PSA and other biomarkers detection in the real sample.