Biowaste-derived carbon nanomaterial-based sensor for the electrochemical analysis of mefenamic acid in the presence of CTAB

Biomass waste can produce valuable products that offer significant economic and environmental benefits. Rice husk is a widely examined agricultural waste due to its lignin, cellulose, and hemicellulose composition, making it suitable for large-scale manufacturing. Because of their special physicochemical, electrical, optical, mechanical, thermal, and biocompatibility qualities, carbon nanomaterials made from rice husk have a wide range of uses in many industries. This study aims to showcase the green synthesis of graphene from rice biomass waste and its potential applications in biomedical research. Researchers used rice husk-derived graphene-modified carbon paste electrode (RHG/CPE) to detect mefenamic acid, a non-steroidal anti-inflammatory drug known to cause harm to patients at higher dosages and listed as a chemical pollutant. The sensor developed using this graphene-based electrode showed high sensitivity and selectivity in detecting mefenamic acid in cetyltrimethylammonium bromide. The surface morphology of RHG was examined using various techniques, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and atomic force microscopy. The sensor's electrochemical characteristics were analyzed using electrochemical impedance spectroscopy. The RHG/CPE sensor could detect mefenamic acid with a detection limit of 2.13 nM and a linear dynamic range of 1.0 × 10−8 to 4.0 × 10−4 M. The sensor showed negligible interference from co-existing molecules, making it suitable for detecting mefenamic acid in human urine, blood serum, breast milk samples, and pharmaceutical tablets with higher recovery. This study demonstrates the potential of using RHG/CPE sensors in biological, pharmaceutical, or environmental samples to detect mefenamic acid.