A comparative Study of Aptasensor Vs Immunosensor for Label-Free PSA Cancer Detection on GQDs-AuNRs Modified Screen-Printed Electrodes

Abstract

Label-free and sensitive detection of PSA (Prostate Specific 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-specific monoclonal antibody, based on graphene quantum dots-gold nanorods (GQDs-AuNRs) modified 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 modified screen printed electrodes. Three techniques are used simultaneously, viz. cyclic voltammetry (CV), differential 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 aptasensor 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 effectiveness. 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.

Electroanalytical Sensor for Diabetic Foot Ulcer Monitoring with Integrated Electronics for Connected Health Application

“…The limit of detection (LoD) and sensitivity were calculated to be 0.71 nM (using the conventional 3σ rule) and 0.67 μA/nM/mm 2 respectively [23]. Such high sensitivity obtained from CV has also been reported by Monika et.al [51]. In order to assess the stability of current response of smart band-aid based sensor with time, chronoamperometry was performed for various tyrosine concentrations and is detailed in Figure S4 (SI).…”

Electrochemical Impedance Spectroscopy Based Biosensors: Mechanistic Principles, Analytical Examples and Challenges towards Commercialization for Assays of Protein Cancer Biomarkers

“…Two modes of operation i. e., voltammetric and EIS techniques exhibited significant potential for reliable detection of the disease. Both sensors detected PSA with an almost same LOD of 0.14 ng mL −1 …”

“…PSA analysis using a label‐free PSA aptasensor and PSA immunosensor was based on graphene quantum dots‐gold nanorods (GQDs‐AuNRs) modified screen‐printed electrodes . Two modes of operation i. e., voltammetric and EIS techniques exhibited significant potential for reliable detection of the disease.…”

Advanced Functional Structure‐Based Sensing and Imaging Strategies for Cancer Detection: Possibilities, Opportunities, Challenges, and Prospects

“…GQDs, another graphene based material, have been paired with AuNRs, and the resulting nanocomposite was used to fabricate a SPE sensor for label‐free sensing of PSA . The modified SPE was investigated in two biosensing formats, i.e., apta‐ and immuno‐sensing.…”

“…The sensitivities of the aptamer‐based sensor were found to be as follows: 3.7 µA ng mL −1 with CV, 2.5 µA ng mL −1 with DPV, and 35 kΩ ng mL −1 with EIS. The corresponding sensitivities for the antibody‐based sensors were as follows: 4.6 µA ng mL −1 with CV, 2.39 µA ng mL −1 with DPV, and 25.6 kΩ ng mL −1 with EIS …”