Evaluation of Reduced Graphene Oxide Modified with Antimony and Copper Nanoparticles for Levofloxacin Oxidation

Abstract

This work presents, for the first time, the oxidation mechanism of levofloxacin combining electrochemical experiments and molecular modelling techniques. Levofloxacin is one of the most widely used antibiotics in the world. The detection of this antibiotic is important, because it cannot be fully assimilated by the human organism, therefore levofloxacin is considerate a hazardous pollutant for environment. Sensors based on reduced graphene oxide (rGO) modified with antimony and copper nanoparticles (NPs) were synthesized, characterized and evaluated for the electrochemical detection of the levofloxacin. The morphological and electrochemical characterization of the composites confirmed that the rGO was modified with the metallic nanoparticles. Molecular modelling studies were performed applying Density Functional Theory (DFT) approach, which indicated that the mechanism of levofloxacin oxidation is given by the loss of two electrons: one from N14 atom and other from C13 atom of the levofloxacin molecule. The glassy carbon electrode (GCE) modified with the SbNPs/rGO and CuNPs/rGO composites were evaluated for the determination of levofloxacin using differential pulse voltammetry (DPV) and achieved detection limit of 4.1×10−8 mol L−1 and 1.7×10−8 mol L−1, respectively, presenting as alternative composites to be used in the analysis of antibiotics.

A Novel Method for the Detection of SARS-CoV-2 Based on Graphene-Impedimetric Immunosensor

“…Using the SWV technique, the proposed sensor detected a concentration of 2.40 ng/mL of the virus. This study shows the potential of the technique and the immunosensor proposed in the SARS-CoV-2 spike protein analysis at low concentrations [ 26 , 27 , 28 ].…”

Determination of Paracetamol on Electrochemically Reduced Graphene Oxide–Antimony Nanocomposite Modified Pencil Graphite Electrode Using Adsorptive Stripping Differential Pulse Voltammetry

“…A screen printed electrode surface was modified with an NiCo 2 O 4 /rGO nanocomposite, which was used to detect hydroylamine [ 23 ], among others. Electrodes based on reduced graphene oxide modified with SbNPs have previously been studied for the detection of organic compounds [ 21 , 24 ]. Cesarino et al [ 21 ] successfully applied rGO-SbNPs dispersed in water and drop-casted onto GCE to determine estriol hormone in water, which yielded an LOD of 0.5 nmol·L −1 [ 21 ].…”

“…Cesarino et al [ 21 ] successfully applied rGO-SbNPs dispersed in water and drop-casted onto GCE to determine estriol hormone in water, which yielded an LOD of 0.5 nmol·L −1 [ 21 ]. Furthermore, Da Silva et al [ 24 ] evaluated SbNPs/rGO and CuNPs/rGO composites on GCE surfaces for the oxidation of levofloxacin using DPV, and the LODs were found to be 4.1 × 10 −8 mol·L −1 and 1.7 × 10 −8 mol·L −1 , respectively [ 24 ]. Our research group previously fabricated a sensor based on electrochemically reduced graphene oxide modified on an in situ plated bismuth pencil graphite electrode [ 25 ] and, recently, an in situ plated thin mercury film modification [ 26 ] was achieved for the detection of trace metals in water.…”

Electrochemical Determination of Levofloxacin Using Poly(Pyrogallol Red) Modified Glassy Carbon Electrode

“…Besides these advantages, conventional electrodes used in electrochemical measurements have poor performance due to the easy fouling of their surfaces by the analyte and the intermediate products formed by the electrode reaction. For this reason, the surfaces of carbon-based electrodes have been altered by utilizing a wide range of modifiers such as nanostructured noble metals [18] and metal oxides, [11,19] carbon-based nanomaterials such as graphene (GR), [20] graphene oxide (GO), [4,6,21,22] carbon nanotube (CNT) [23] and conductive polymers [2,5,20,24] for selective and sensitive LEV detection. Conductive polymers are one of the most frequently used modifiers due to their homogeneity, repeatability, good stability, and strong adhesion to the electrode surface.…”