Highly sensitive voltammetric immunosensor for the detection of prostate specific antigen based on silver nanoprobe assisted graphene oxide modified screen printed carbon electrode.

In this work, we developed an effective voltammetric immunosensing platform for the sensitive detection of prostate specific antigen (PSA) utilizing a graphene oxide (GO) modified screen-printed carbon electrode (SPCE) hybridized with the ex-situ prepared silver nanoparticles (AgNPs) as a probe and signal transducer. The sensing platform comprises a direct-type immunoassay involving the selective interaction of PSA with anti-PSA. The surface morphology and analytical performance of the modified SPCE were characterized through relevant instrumentations. The changes in the voltammetric reduction current of AgNPs at 0.11 V in the sensor electrode was correlated to the PSA concentration. Under optimum conditions, the fabricated immunosensor exhibited a sensitive response to PSA with a limit of detection (LOD) of 0.27 ng mL-1 and a dynamic calibration range of 0.75-100.0 ng mL-1. We demonstrated that the participation of AgNPs along with GO modification contribute to the desired signal amplification and sensitive detection of PSA. It is anticipated that the proposed immunosensor can serve as a biomarker and potentially be utilized for the real sample quantification of PSA.