A Novel Electrochemical Sensing of 8-Hydroxy-5-Nitro-Quinoline Moiety using Graphene-Oxide Fabricated Glassy Carbon Electrode

Abstract

In this work, graphene-oxide nanofilm modified glassy carbon electrode (GO@GCE) as a highly sensitive electrochemical sensor was developed and used as electrocatalyst for the detection of pharmaceutically active 8-hydroxy-5-nitro-quinoline (HNQ) moiety, for the first time. Electrochemical behaviour of HNQ moiety on the fabricated sensor was explored by CV, CC, EIS, DPSV techniques and results indicated that the electrode process was diffusion controlled influenced by the adsorption. Spectra of EIS exhibited a big decrease in charge transfer resistance (R_ct), which refers the highest conductivity with the GO@GCE sensor as compared to bare GCE, TiO₂@GCE, and f-MWCNT@GCE electrocatalysts. Under optimized conditions, cathodic peak current in differential pulse stripping voltammograms as well as cyclic voltammograms gave a linear increasing response of HNQ reduction over a concentration range of 29.7-115.4 μmol L^-1 and 29.7-222.2 μmol L^-1 respectively with a regression factor of 0.998 and 0.987 correspondingly. The GO@GCE sensor revealed tremendous electrocatalytic features with great promise for sensitivity, repeatability, reproducibility, and quantitative/qualitative screening, detection toward reduction of nitro group in HNQ moiety. Finally, the proposed GO@GCE sensor was effectively applied for the fast laboratory assay of HNQ moiety in neutral universal buffer as supporting electrolyte.

GRAPHICAL ABSTRACT

Key words:

• 8-Hydroxy-5-nitro-quinoline (nitroxoline)
• graphene-oxide fabricated GCE
• cyclic voltammetry
• chronocoulometry
• electrochemical impedance spectroscopy
• differential pulse stripping voltammetry