Anti-Prostate Specific Antigen (Anti-PSA) Modified Interdigitated Microelectrode-Based Impedimetric Biosensor for PSA Detection

Interdigitated microelectrodes (IDEs) functionalized with a cysteamine (Cys) self-assembled monolayer (SAM) were used to fabricate a sensitive, disposable, impedimetric biosensor for prostate specific antigen (PSA) detection. PSA specific monoclonal antibody (anti-PSA) was covalently immobilized on cysteamine modified gold surface of IDEs, using N-ethyl-N’-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) chemistry. Bovine serum albumin (BSA) was used as a blocker to prevent nonspecific adsorption on electrode surface. BSA-anti-PSA/Cys/IDE electrodes were exposed to solutions with different PSA concentrations and their response was measured using a label-free electrochemical impedance (EIS) technique. The impedance changes revealed close a correlation with PSA concentrations in the measurement range of 1 pg.mL−1–100 ng.mL−1, with sensitivity of 0.444mL.g−1.