Engineering Low Cost ZnO/RGO Nanocomposite for the Picomolar Sensing of Epinephrine, Uric Acid and Tyrosine

Abstract

This paper demonstrates a highly sensitive, selective, biocompatible and cost-effective method for the simultaneous determination of Epinephrine (EPN), Uric acid (UA) and Tyrosine (TYR). Superior electrochemical performance was achieved using ZnO/RGO/CPE modified electrodes compared to individual components, graphene oxide (GO) and ZnO modified electrodes. The electrochemical activity of the fabricated sensor is examined through cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CA). A sharp increase in anodic peak current and negative shift in the electrode potential upon modification indicates enhanced electrocatalytic activity of ZnO/RGO/CPE. Well distinguishable voltammetric peaks with base-to-base separation and better anodic current were achieved with modified electrode in a mixture of EPN, UA and TYR. The developed sensor exhibits good electrocatalytic activity and an excellent rate of electron transfer arising from the synergistic effect of ZnO and RGO. The detection limit of each biomolecule calculated using DPV is 310 pM for EPN, 340 pM for UA and 730 pM for TYR. The practical feasibility of the proposed sensor is demonstrated by recording satisfactory voltammetric responses in human urine and serum samples.

An amorphous zinc/copper double transition metal hydroxides for electrochemical simultaneous detection of dopamine, serotonin, and melatonin

“…55 In the FTIR spectrum of ZnCu-TMH, the peaks observed in the range of 470 cm −1 correspond to the stretching vibrations of the metal–oxygen bond. 56,57…”

“…55 In the FTIR spectrum of ZnCu-TMH, the peaks observed in the range of 470 cm À1 correspond to the stretching vibrations of the metaloxygen bond. 56,57 The structures of the ZnCu-TMH nanocomposites were investigated by XRD, as shown in Fig. 1F.…”

Development of a Non-Enzymatic Vitamin-C Electrochemical Sensor Based on rGO/Ce2(SO4)3Hierarchical Nanocomposite

“…Recently, graphene derivatives -inorganic composites including CuS/rGO, MoS 2 /rGO, Au/rGO, Ni/rGO, ZnO/rGO, CeO 2 /rGO, have gained immense attention in developing electrochemical sensors. [22][23][24][25][26][27] Most of the graphene derivatives exhibit excellent detection efficacies owing to their tuneable physicochemical attributes, surface functionalities and unique morphological architect. Majorly, surface attribute such as high specific surface area is a key for enhanced detection of biomarkers and biomolecules like AA.…”

Modified Sawhorse Waveform for the Voltammetric Detection of Oxytocin

“…16,18 Using FSCV along with CFMEs provides for rapid analysis with a high degree of accuracy for representative biomolecule concentration changes in the brain. [18][19][20] This technique was used to detect monoamines in the brain such as dopamine 21 serotonin, 22,23 norepinephrine, 24 amino acids, [25][26][27] and others 28 Recently, it has been adapted for the measurement of DNA and 29 biomolecules 30 and the detection of hormones 31 and neurochemicals. 32 FSCV has also been used to detect analytes that foul such as melatonin in live mesenteric lymph node slices, further exemplifying the versatility of this technique.…”