Microporous Polymer-Modified Glassy Carbon Electrodes for the Electrochemical Detection of Metronidazole: Experimental and Theoretical Insights

Abstract

The persistence and potential toxicity of emergent pollutants pose significant threats to biodiversity and human health, emphasizing the need for sensors capable of detecting these pollutants at extremely low concentrations before treatment. This study focuses on the development of glassy carbon electrodes (GCEs) modified by films of poly-tris(4-(4-(carbazol-9-yl)phenyl)silanol (PTPTCzSiOH), poly-4,4′-Di(carbazol-9-yl)-1,1′-biphenyl (PCBP), and poly-1,3,5-tri(carbazol-9-yl)benzene (PTCB) for the detection of metronidazole (MNZ) in aqueous media. The films were characterized using electrochemical, microscopy, and spectroscopy techniques, including scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Monomers were electropolymerized through cyclic voltammetry and chronoamperometry techniques. Computational methods at the B3LYP/def2-TZVP level were employed to investigate the structural and electrochemical properties of the monomers. The electrochemical detection of MNZ utilized the linear sweep voltammetry technique. Surface characterization through SEM and XPS confirmed the proper electrodeposition of polymer films. Notably, MPN-GCEs exhibited higher detection signals compared to bare GCEs up to 3.6 times in the case of PTPTCzSiOH-GCEs. This theoretical study provides insights into the structural, chemical, and electronic properties of the polymers. The findings suggest that polymer-modified GCEs hold promise as candidates for the development of electrochemical sensors.

A Novel Poly(cytosine)-Based Electrochemical Biosensor for Sensitive and Selective Determination of Guanine in Biological Samples

“…On the other hand, the oxidative peak current of G at the poly­(cytosine)/GCE increased with pH values increasing from 3.5 to 5.0 (curve (b) of Figure B) after then decreasing at pH regions beyond 5.0 (curve (b) of Figure B), which may be attributable to the interaction of the G with the electrode-modifying materials. G presents a p K a value of 4.2, and the increasing current trend in the acidic region might account partly for the possible attraction between guanine and the cytosine (p K a 9.2) deposited by electropolymerization in the reduced form. , …”

“…G presents a pK a value of 4.2, and the increasing current trend in the acidic region might account partly for the possible attraction between guanine and the cytosine (pK a 9.2) deposited by electropolymerization in the reduced form. 27,28 3.7. Effect of Scan Rate on I pa and E Pa of G Oxidation.…”