Wash-less and highly sensitive assay for prostate specific antigen detection

Abstract

A novel, simple and facile biosensor for prostate specific antigen (PSA) detection was constructed. In this method, proteolytically active PSA is capable of cleaving PSA substrate–magnetic carrier complexes. Electrochemical analysis of the sensor layer showed a significant decrease in impedance signal after proteolysis has occurred, whereas a positive change in impedance was observed using a negative control substrate, indicating the specificity of our detection mechanism. The biosensor has the ability to monitor PSA concentrations ranging from 1 pg ml⁻¹ to 1 μg ml⁻¹ with a detection limit as low as 1 pg ml⁻¹. The sensor offers the possibility of developing a wash-less and cost-effective point-of-care device due to the simplicity of the probe immobilization process and the elimination of labeling and reporter molecules during the biosensing step.