Label-free PSA electrochemical determination by seed-mediated electrochemically-deposited gold nanoparticles on an FTO electrode.

A facile and sensitive approach is introduced to precisely determine trace amounts of prostate specific antigen (PSA) by gold nanostructures deposited on fluorine-doped tin oxide (FTO) electrodes. The gold electrode fabrication is carried out by integration of two techniques of vacuum-deposition and electrochemical growth. The electrode was successfully used as a label-free immunosensor for PSA determination in human serum samples. The dependency of the biosensor performance on various fabrication parameters have been investigated and the optimized fabrication rout has been specified. This label-free immunosensor presents a noticeable performance with a large range of linearity from 0.05 to 30 ng/mL, a low detection limit of 5.7 pg/mL, and a long-term stability of 4 weeks. The obtained results for PSA determination in real samples show a good agreement with ELISA results with less than 10% deviation. [ABSTRACT FROM AUTHOR]