Impedimetric immunosensor for the NS1 dengue biomarker based on the gold nanorod decorated graphitic carbon nitride modified electrode

Abstract

Dengue has been a threatening vector-borne viral disease across different countries of the world. NS1 is a non-structural dengue biomarker that is released into the bloodstream during the initial stages of the infection and is used in the early diagnosis of the disease. In this work, we present a high-performance NS1 immunosensor based on gold nanorod decorated graphitic carbon nitride (AuNRs-g-C3N4) modified glassy carbon electrodes (GCE). AuNRs-g-C3N4 composite is synthesized, which possesses excellent electro-activity, fast electron transfer kinetics, and high catalytic property. NS1 antibody is immobilized onto the surface of the AuNRs-g-C3N4 modified GCE and used as an impedimetric sensing probe for the quantitative sensing of NS1 antigen through electrochemical impedance spectroscopy. We have chosen [Fe (CN)6]3−/4− as a redox couple to observe the respective changes in charge transfer resistance (Rct) associated with antigen bonding with an antibody both in PBS buffer as well as in human serum. The prepared immunosensor shows an excellent electrocatalytic response for the quantitative determination of NS1. The analytical parameters obtained by using this immunosensor are found comparable or better to previously reported NS1 sensors and open new insights with great potential for the application of point of care besides application in the diagnosis of Dengue.