MnO₂ Nanoclusters Decorated on GrapheneModified Pencil Graphite Electrode for Non‐Enzymatic Determination of Cholesterol

Abstract

Electrochemically deposited MnO 2 on graphene coated Pencil Graphite Electrode (PGE) has been used to develop a facile electrochemical sensor for the determination of Cholesterol. Cyclic voltammetric (CV) studies and electrochemical impedance spectroscopic (EIS) technique were used to investigate the electrochemical properties of the modified sensing platform. The physicochemical properties of the modified electrodes were characterized by X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental conditions such as effect of scan rate, concentration and pH were optimized. The linear dynamic range for the determination of Cholesterol was found to be 12 × 10 À 10 M-240 × 10 À 10 M under optimum conditions. The ultralow level of detection limit (0.42 nM) demonstrates the high sensitivity of the proposed method. The developed method was successfully applied for the non-enzymatic determination of Cholesterol in human blood samples at ultralow levels.

Non-enzymatic electrochemical determination of salivary cortisol using ZnO-graphene nanocomposites

“…The above-mentioned process was repeated to trim down the graphene layer for achieving improved-quality graphene. 25,35–37 …”

“…The above-mentioned process was repeated to trim down the graphene layer for achieving improved-quality graphene. 25,[35][36][37] Preparation of ZnO/GR/PGE. PGE with a dimension of 0.65 cm 2 was pretreated with 1.0 M H 2 SO 4 and rinsed in doubledistilled water.…”

“…Graphene is contemplated as a prospective nanoscale building block for a variety of applications including gas sensors, field-effect transistors, and electromechanical resonators with its distinctive electronic properties originating because of the electron confinement. 25 Graphene-modified electrodes were prepared by Kim et al for the electrochemical detection of dopamine in the presence of ascorbic acid. 26 Similarly, Jahani and co-workers employed NiO nanoparticles decorated on the graphene nanosheets modified screen-printed electrodes for selective detection of dopamine in presence of uric acid.…”

Emerging Trends in Non-Enzymatic Cholesterol Biosensors: Challenges and Advancements

“…It has been found that the electrode showed a wide linear range for the measurement of cholesterol, from 12 × 10 −10 M to 240 × 10 −10 M, under optimum conditions, with a low detection limit of 0.42 nM. The results demonstrated that the electrode has excellent sensitivity for cholesterol [77]. Rison et al, as illustrated in Figure 10, reported a non-enzymatic cholesterol biosensor based on MnO2 nanoclusters immobilized on a graphene-modified pencil graphite electrode (MnO2/GR@PGE).…”

“…It has been found that the electrode showed a wide linear range for the measurement of cholesterol, from 12×10 −10 M to 240×10 −10 M, under optimum conditions, with a low detection limit of 0.42 nM. The results demonstrated that the electrode has excellent sensitivity for cholesterol [77]. Agnihotri et al presented a non-enzymatic approach toward cholesterol detectionusing β-cyclodextrin-functionalized graphene.…”