Electrocatalytic Activity Enhancement Using Graphene-Metal Oxide Nanocomposites for the Ultra Low Level Detection of Biomolecules

Abstract

Metal oxide reduced graphene oxide (MO/RGO, MO = NiO, Co3O4 and SnO2) nanocomposites were synthesized by cost-effective hydrothermal method. The structural, thermal, and morphological characteristics of composites were investigated using PXRD, FT-IR, TGA, Raman, SEM and HR-TEM. Modified carbon paste electrochemical sensors based on NiO/RGO, Co3O4/RGO and SnO2/RGO were developed and compared for the effective detection of Epinephrine (EPN), Serotonin (SER) and Tyrosine (TYR). The performance of the NiO/RGO/CPE sensor was superior to other composites modified electrodes. The electrochemical measurements were studied by cyclic voltammetry, differential pulse voltammetry, chrono amperometry, and electrochemical impedance spectroscopy. The modified electrodes showed excellent electrocatalytic activity towards EPN, SER, and TYR arising from the synergistic effect of reduced graphene oxide and metal oxide. The excellent electrical conductivity imparted by direct interphase of RGO to semiconductive metal oxide, increased surface area and the increased number of active sites favor the sensitive determination of bio molecules. The NiO/RGO/CPE facilitated the analysis of EPN, SER, and TYR with lower detection limit of 158, 165, and 519 pM, respectively. The peaks for the three biomolecules are well separated from each other and the electrodes were effectively used for real samples

Sensitive Detection of Trace Vitamin C via Enzyme-like Catalysis of S Defect-Rich Ultrathin 2D MoS2: Comprehensive Innovative Experiments on Two-Dimensional Materials for Undergraduates

“…Two-dimensional materials like graphene, 12−14 TMDs, 15 or LDHs 16 have become the most promising candidates for enzyme-like catalysis thanks to their unique physical and chemical properties (ultrathinness, large specific surface area, and electronic mobility in two-dimensional space 17 AA or biochemical components include cobalt oxyhydroxide nanoflakes, 18 graphene, 19 and MoTe 2 , 20 but they are not sensitive enough, and they take too long to detect AA. The S defect-rich ultrathin 2D MoS 2 21 made in our laboratory was used to produce a blue product (ox TMB) by enzyme-like catalytic oxidation of TMB in the presence of H 2 O 2 .…”

“…Two-dimensional materials like graphene, − TMDs, or LDHs have become the most promising candidates for enzyme-like catalysis thanks to their unique physical and chemical properties (ultrathinness, large specific surface area, and electronic mobility in two-dimensional space), which have attracted wide interest among researchers. Examples of 2D materials that have already been used for the detection of AA or biochemical components include cobalt oxyhydroxide nanoflakes, graphene, and MoTe 2 , but they are not sensitive enough, and they take too long to detect AA.…”

A Novel Molecularly Imprinted Electrochemical Sensor Based on PANI@GO for Highly Sensitive and Selective Analysis of Trace Epigoitrin

“…While, the analytical performance of MIES is frequently limited by the properties of the electrode surface modification materials, and the use of nanomaterials with excellent electrical conductivity for modifying the electrodes has become an effective way to solve the above problems. 24,25 Graphene oxide (GO) is a popular material with unique characteristics such as high surface area and considerable charge carrier conductance. Many studies have shown that GO combined with other materials exhibits excellent electrochemical properties.…”