Self assembled monolayers versus iron oxide nanoparticles modified surfaces: Two functionalization strategies for femtomolar detection of prostate specific antigen: Comparative study between two electrochemical biosensors for femtomolar detection of prostate specific antigen

Two electrochemical immunosensors were investigated for prostate specific antigen detection. The first one was functionalized with 3-glycidypxypropyltrimethoxysilane self-assembled monolayer, while the second one was based on iron oxide nanoparticles functionalized with 3-aminopropyltriethoxysilane. Electrochemical impedance spectroscopy and square wave voltammetry have been investigated to follow-up the prostate specific antigen detection in a phosphate buffer solution and in a human serum. The limit of detection of both immunosensors was found of order of 10 fg/ml.