Electrochemical detection of prostate-specific antigen based on gold colloids/alumina derived sol-gel film

An electrochemical immunosensor for total prostate-specific antigen (PSA) was fabricated based on anti-PSA antibody-functionalized gold colloids/alumina sol-gel film. The presence of colloidal gold provides a good microenvironment for the immobilization of biomolecules. The fabrication process of the immunosensor was characterized by cyclic voltammetry. A direct electrochemical immunoassay format was employed to detect PSA on the basis of the potential change before and after the antigen–antibody interaction. Under optimal conditions, the potential change was proportional to PSA concentration ranging from 4.0 to 13 ng mL− 1 with a detection limit of 3.4 ng mL− 1. In addition, the performance and factors influencing the performance of the immunosensor were investigated and optimized.