Facile Synthesis of Ag/AgVO₃/N-rGO Hybrid Nanocomposites for Electrochemical Detection of Levofloxacin for Complex Biological Samples Using Screen-Printed Carbon Paste Electrodes

Abstract

Silver vanadate nanorods (β-AgVO3) with silver nanoparticles (Ag-NPs) decorated on the surface of the rods were synthesized by using simple hydrothermal technique and later anchored onto nitrogen-doped reduced graphene oxide (N-rGO) to make a novel nanocomposite. Experimental analyses were carried out to identify the electronic configuration by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis, which revealed monoclinic patterns of the C12/m1 space group with Wulff construction forming beta silver vanadate (β-AgVO3) crystals with optical density and phase transformations. Ag nucleation showed consistent results with metallic formation and electronic changes occurring in [AgO5] and [AgO3] clusters. Transmission electron microscopy and field-emission scanning electron microscopy with elemental mapping and EDX analysis of the morphology reveals the nanorod structure for β-AgVO3 with AgNPs on the surface and sheets for N-rGO. Additionally, a novel electrochemical sensor is constructed by using Ag/AgVO3/N-rGO on screen-printed carbon paste electrodes for the detection of antiviral drug levofloxacin (LEV) which is used as a primary antibiotic in controlling COVID-19. Using differential pulse voltammetry, LEV is determined with a low detection limit of 0.00792 nm for a linear range of 0.09–671 μM with an ultrahigh sensitivity of 152.19 μA μM–1 cm–2. Furthermore, modified electrode performance is tested by real-time monitoring using biological and river samples.

An amphiprotic paper-based electrode for glucose detection based on layered carbon nanotubes with silver and polystyrene particles

“…In the previous reports, 56,58,60,61,65 Ag-based electrodes showed excellent redox performance for different species. The oxidation reaction mechanisms of Ag nanoparticles in basic solution were attributed to the generation of the strong oxidant AgO(OH) 2 , 65 whereas their mechanisms for glucose redox in neutral 66–68 and acidic solutions were not clear. 69–71 For the current CNT-NH 2 –Ag/PS paper electrode, the redox reaction of glucose was performed in a neutral solution (Na 2 SO 4 system).…”

“…These results indicated that the redox reaction on the CNT-NH 2 -Ag/PS paper electrode was a diffusion-controlled electrochemical process. [62][63][64] whereas their mechanisms for glucose redox in neutral [66][67][68] and acidic solutions were not clear. [69][70][71] For the current CNT-NH 2 -Ag/PS paper electrode, the redox reaction of glucose was performed in a neutral solution (Na 2 SO 4 system).…”

Electrochemical Sensor Nanoarchitectonics for Sensitive Detection of Uric Acid in Human Whole Blood Based on Screen-Printed Carbon Electrode Equipped with Vertically-Ordered Mesoporous Silica-Nanochannel Film

“…As an organic combination of carbon electrode and screen-printed electrode, screen-printed carbon electrodes (SPCEs) have unique characteristics including high chemical stability, wide potential window, good biocompatibility, low cost, easy mass production, and disposable use [ 13 , 14 , 15 ]. However, it was proven that VMSF cannot be stably grown on carbon electrodes.…”

“…Compared with conventional solid electrodes (e.g., glassy carbon electrode-GCE, Au or Pt electrode), screen-printed electrodes (SPEs) have attracted much attention owing to their low cost, easy batch fabrication, convenient array and flexible design, and possibility of low sample consumption [ 10 , 11 , 12 ]. Amongst alternatives, screen-printed carbon electrodes (SPCEs) have great potential in the detection of biomarkers in clinical samples owing to the merits of a wide potential window, low background current, high biocompatibility, and excellent chemical stability [ 13 , 14 , 15 ]. However, modification of electrode surfaces to improve the anti-interference ability and sensitivity are urgently needed for direct analysis of complex samples with high performance.…”

Intermolecular hydrogen bonds between catechin and theanine in tea: slow release of the antioxidant capacity by a synergetic effect

“…20 However, there has been little research on the effects of the interaction of various ingredients in tea on the antioxidant capacity and the mechanism of their action, the traditional in vitro antioxidant detection method uses a UV-spectrophotometer to detect changes in the content of various color components, but this will be affected by the color and turbidity of the sample itself, so that the result is a large error, while electrochemical sensors have been widely used in food detection because of their high sensitivity, good selectivity, low cost, and fast analysis speed. 21–23 Therefore, the use of electrochemical technology to explore the synergistic effect of theanine on the antioxidant capacity of catechin can not only allow consumers to clear the mechanism of action to understand the benefits of drinking tea, but also promote the development of the food industry.…”