New Processes and Materials Based on Electrochemical Concepts at the Microscopic Level Symposium, MicroEchem 2013 Sandwich-type ELISA impedimetric immunosensor for early detection of prost ate-specific antigen (PSA) in human serum

Early detection of cancer is vital for the successful treatment of the disease. Hence, a rapid and sensitive diagnosis is essential before the cancer is spread out to the other body organs. A gold millielectrode (GME) functionalized with a mixed (16MHA+EG3SH) self-assembled monolayer (SAM) was used to fabricate a point-of-care immunosensor for the detection of the p rostate cancer biomarker: prostate-specific antigen (PSA) in human serum samples. An organic matrix (Amine-PEG3biotin/Avidin) was used to reduce non-specific protein adsorption on the electrode surface. A 16-MHA/EG3SH/Amine-PEG3biotin/Avidin GME was exposed to solutions with different sandwich-type immunocomplex ( Btn Ab-AgPSA- HRP Ab) concentrations and its response was measured using the electrochemical impedance spectroscopy (EIS) technique. This approach was compared w ith regard to a reference ELISA immunoassay. The obtained results showed that the immunosensor proposed in this work q ualifies for its pre-clinical application in the quantification of PSA in se rum samples of a representative Mexican population. © 2014 The Authors. Published by Elsevier B.V. Selection and peer-review under responsibility of the Sociedad Mexicana de Electroquimica.