Synthesis of cerium oxide/sulphur doped graphitic carbon nitride nanocomposite for development of electrochemical sensor to detect antimicrobial drug metronidazole.

Abstract

Metronidazole is a well-known antibacterial medication belonging to the nitroimidazole class that is commonly used to treat infections. But the problem of its presence in aquatic habitats is getting worse. This work used thermal condensation of thiourea at 550°C to create sulphur- doped graphitic carbon nitride (S-g-C3N4). Furthermore, CeO2/sulphur-doped g-C3N4 (CeO2/CNS) nanocomposites were synthesized by one-pot thermal condensation from cerium nitrate and thiourea as starting materials. The resulting nanocomposites' crystalline and structural characteristics were examined using a variety of characterisation techniques. A basic drop-casting method was used to apply the CeO2/CNS nanocomposite to a glassy carbon electrode (GCE). This modified electrode was then utilized for electrochemical analysis of metronidazole via cyclic voltammetry (CV). Comparing the CeO2/CNS/GCE to the bare electrode and CNS/GCE, a significant improvement in the reduction peak current was seen. This improvement is attributed to reduced charge transfer resistance and increased electron transfer efficiency. The electroactive surface area of the modified sensor was 0.176cm2, which is around 1.4 times larger than the bare electrode. It was observed that the reduction of metronidazole was a diffusion-controlled process. The CeO2/CNS/GCE exhibited a limit of detection (LOD) of 37 μM, demonstrating its high sensitivity for detecting metronidazole.