Ultrasensitive Electrochemical Detection of Prostate-Specific Antigen (PSA) Based on Graphene-Silver Nanocomposite

In this work, the electrostatic layer-by-layer (LbL) assembly of bovine serum albumin (BSA) functionalized graphene nanosheets and silver nanoparticle (AgNP), along with the thermal annealing at 340 degrees C in air were performed to prepare a thin and uniform film of AgNP embedded porous graphene (AgEPG). To determine prostate specific antigen (PSA) in human serum, we proposed a new electrochemical immunosensor based on a protein tracer, namely the functionalized AgEPG. Our proposed immunosensor was feasible to detect PSA (1-35 ng/mL) under optimal electrochemical and immunoreactions determination conditions, and the limit of detection (LOD) was calculated as 0.44 ng/mL.