A sustainable Non-Enzymatic Approach for Determination of Cholesterol Using Piper nigrum Derived Porous Carbon/ α -Fe 2 O 3 Composite Electrode

Abstract

Activated porous carbon (APC) obtained from Piper nigrum along with α -Fe 2 O 3 have been used to modify carbon paste electrode (CPE) for the highly sensitive and selective electrochemical determination of cholesterol. The enhanced synergistic properties observed between the biomass-derived APC and α -Fe 2 O 3 uplifts the electrocatalytic activity of the modified electrode (APC-Fe 2 O 3 /CPE). The prepared α -Fe 2 O 3 nanoparticles were characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Dynamic light scattering (DLS), zeta potential measurements and Thermogravimetric analysis (TGA). High resolution transmission electron microscopy (HRTEM), Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and electrochemical techniques were used to study the physico-chemical properties of the modified electrodes. Experimental conditions such as effect of pH, scan rate and concentration of cholesterol were optimized. Wide linear dynamic range between 25 nM and 300 nM, low limit of detection (LOD) and limit of quantification (LOQ) of 8 nM and 26 nM respectively make the method very effective and sensitive. Cholesterol in human blood serum samples was non-enzymatically determined using the developed method.