SURFACE PLASMON RESONANCE BIOSENSOR BASED ON GRAPHENE WRAPPED CYSTEINE SELF-ASSEMBLY FOR CARDIAC TROPONIN I

Abstract

This dissertation contains results of the studies related to the fabrication of a label free biosensor based on reduced graphene wrapped cysteine (rGO-Cys) self assembled on gold (Au) electrode for the detection of cardiac troponin I (cTnI) using electrochemical and surface plasmon resonance (SPR) techniques. The rGO-Cys were characterized using transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy (FT-IR) and contact angle (CA) measurements. Further, SPR studies were used to investigate the immobilization process and the binding kinetics of antigen-antibody interactions and it was observed that 11.7ng of anti-cTnI has been immobilized on the surface of Au electrode under optimized conditions. The response studies carried out using electrochemical impedance spectroscopy shows that the fabricated bio-electrode has sensitivity of 0.0642Ω mLng−1cm-2, linear detection range of 1-80 ngmL-1, linear regression coefficient of 0.9956 and lower detection limit of 0.0697 ngmL−1.