A Sensitive and One-Step Quantification of Thyroid Stimulating Hormone Using Nanobiosensor

Abstract

Abstract We present a sensitive single step nanobiosensor for thyroid disease diagnosis. Nanoparticles modified screen printed carbon electrode catalyzes the formation of peptide bond between anti-TSH antibody and amino coated gold nanoparticles rendering a covalently coupled antibody. The nanobiosensor detects and quantifies the thyroid stimulating hormone in the sample by sensing the effective resistance offered by electrode. As the TSH concentration increases in serum sample, more is the immunocomplex formed and higher is the resistance offered by electrode. Gold nanoparticles functionalization with cystamine dihydrochloride facilitates a covalent bonding between surface amino group and carboxylic Fc ensuring maximizing available active antibody. This strategy ensures a much lower limit of detection in addition to improved detection range due to increased loading capacityas a result of larger effective surface area offered by gold nanoparticles. These two aspects of immunosensor fabrication resulted in limit of detection as low as 0.001 µIU/mL and an enhanced detection range of 0.001–150 µIU/mL. This makes the developed immunosensor suitable for diagnostic purpose covering the clinically relevant range and a simple detection technique makes it potential candidate for fabrication of a Point-of-Care device for detection of Thyroid dysfunctioning.