A comparative Study of Aptasensor Vs Immunosensor for Label-Free PSA Cancer Detection on GQDsAuNRs Modifed Screen-Printed Electrodes

Abstract

Label-free and sensitive detection of PSA (Prostate Specifc Antigen) is still a big challenge in the arena of prostate cancer diagnosis in males. We present a comparative study for label-free PSA aptasensor and PSA immunosensor for the PSA-specifc monoclonal antibody, based on graphene quantum dotsgoldnanorods (GQDs-AuNRs) modifed screen-printed electrodes. GQDs-AuNRs composite has been synthesized and used as an electro-active material, which shows fast electron transfer and catalytic property. Aptamer or anti-PSA has immobilized onto the surface of modifed screen printed electrodes. Three techniqu s are used simultaneously, viz. cyclic voltammetry (CV), diferential pulse voltammetry (DPV) and electrochemical impedence spectroscopy (EIS) to investigate the analytical performance of both PSA aptasensor and PSA immunosensor with its corresponding PSA antigen. Under optimum conditions, both sensors show comparable results with an almost same limit of detection (LOD) of 0.14 ng mL−1. The results developed with ptasensor and anti-PSA is also checked through the detection of PSA in real samples with acceptable results. Our study suggests some advantages of aptasensor in terms of better stability, simplicity and cost efectiveness. Further our present work shows enormous potential of our developed sensors for real application using voltammetric and EIS techniques simultaneous to get reliable detection of the disease