Fe3O4/PEDOT:PSS nanocomposite as an advanced electroconductive material for biosensing of prostate specific antigen in unprocessed human plasma samples
A novel sandwich-type biosensor based on signal amplification strategy of various nanocomposites was developed to monitoring of prostate specific antigen (PSA) in real samples. The engineered immunosensor fabricated by iron oxide magnetic nanoparticles modified polymer poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) [Fe3O4/PEDOT.PSS] conductive nanocomposite that utilized to immobilization of primary antibodies (biotinylated antibody (Ab1)). In order to improve electron transfer rate, cysteamine caped gold nanoparticle (AuNPs-Cys A) was applied to conjugation with secondary antibody (HRP-Ab2). All of the fabrication procedure was investigated by square wave voltammetry technique. Under optimized experimental condition, the calibration curve showed wide linear range (0.001-0.5 µg/L) for PSA biomarker with low limit of quantification 0.001 µg/L. Finally, satisfactory results were obtained for the determination of PSA in untreated human plasma samples and indicating the potential of the immunoassay to be applied in clinical bioanalysis.