Electrochemical Investigation of Viral Respiratory Infection Inflammatory Biomarker Protein by Using AuNPs Modified Electrode

A novel electrochemical immunoelectrode was fabricated for Serum Amyloid A protein (SAA) sensing using gold nanoparticles modified electrode. The present study reports the optimization of electrochemical deposition parameters for gold nanoparticles (AuNPs) on ITO (Indium-tin-oxide) surface. AuNPs were electrochemically deposited on APTES (3-Aminopropyl) triethoxysilane) modified ITO surface to prepare the working electrode (AuNPs/APTES/ITO). This electrode is further used to fabricate immunoelectrode SAA-Ab/AuNPs/APTES/ITO by immobilizing SAA-specific antibodies (SAA1/2 Ab) on its surface. Characterization of prepared immunoelectrode is done by electrochemical characterization techniques (differential pulse voltammetry, cyclic voltammetry, electrochemical impedance spectroscopy), scanning electron microscopy, and XRD. Sensing by electrochemical techniques revealed that fabricated immunoelectrode can detect SAA when 10 mu l of it (from an initial concentration of 10 fg ml(-1) to 105 fg ml(-1)) is poured on the immunoelectrode and kept for 10 min every time. The linearity equation is obtained with the lowest used concentration of SAA biomarker 10 fg ml(-1) and the limit of detection (LOD) has been calculated using the equation 3 sigma/sensitivity which comes out to be 6.867 fg ml(-1).