Modified carbon based electrodes for electrochemical sensing of biomolecules

Abstract

Now-a-days a large variety of biological analytes are detected by highly sensitive newlineelectrochemical sensors which are inexpensive and simple as compared to conventional methods such as UV-vis absorption spectroscopy, spectrofluorometry, HPLC and gas chromatography. Electrochemical analysis is exceptional owing to its economical, low energy consuming and unique approach in the method design, and high sensitivity for the analyte determination. Carbon based electrochemical sensors are commonly used because of their low cost, good electron newlinetransfer kinetics, good chemical stability, and biocompatibility. Recently electrochemical properties of pencil graphite electrodes (PGEs) have been explored in the analysis of various organic compounds. High electrochemical reactivity, easy modification, commercial accessibility, fine rigidity, disposability and low-cost of PGE make it ideal to be used as an effective working electrode. The thesis presented explains different modified PGEs have been employed in the electrocatalytic determination biomolecules such as cholesterol, cortisol, Vitamin B6 and morin. newlineThe modified electrodes are effectively used for the ultra-level sensing of these biomolecules in real samples. The electroactive surface area and the conduvtivity of bare PGE is enhanced newlinedifferent electrode modifiers such as and#946;-CD, graphene, conducting polymer, metal oxides and metal nanoparticles. The modified electrodes are found to exhibit good electrocatalytic behavior towards the target biomolecules. Cyclic voltammetric (CV) studies and electrochemical impedance spectroscopic (EIS) technique were used to investigate the electrochemical properties of the modified sensing platform. The newlinemorphology and step wise fabrication process of the modified electrodes were characterized byvii Ramana spectroscopy, X-ray photoelectron spectroscopy (XPS),scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR).