• Thomas, Tony

Abstract

<jats:title>Abstract</jats:title><jats:p>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</jats:p>

Topics

• nanocomposite
• impedance spectroscopy
• surface
• Carbon
• scanning electron microscopy
• transmission electron microscopy
• thermogravimetry
• electrical conductivity
• cyclic voltammetry
• pulse voltammetry
• cloud-point extraction
• amperometry