Strontium phosphate/functionalized carbon nanofiber composite: A promising electrode material for amperometric detection of flufenamic acid

Recent advances to utilize two or more nanoparticles for developing novel sensors with superior sensitivity have spurred advanced detection limits even at low concentrations. In this research, a blend of rutheniumdoped TiO2 (Ru-TiO2) nanoparticles and multiwalled carbon nanotubes (MWCNTs) loaded into carbon paste matrix to fabricate a novel Ru-TiO2/MWCNTs-CPE sensor was used for the detection and quantification of flufenamic acid (FFA) and mefenamic acid (MFA) drugs. The surface morphology of Ru-TiO2 was assessed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). Sensitivity and selectivity of the electrode was improved at the Ru-TiO2/MWCNTs modified CPE compared to nascent CPE due to the amazing surface distinctive characteristics of the modifier at pH 5.0. The effect of concentration of the modifier, pH, pre-concentration time, sweep rate and concentration on signal enhancement of FFA and MFA was studied. The square wave voltammetry (SWV) currents are linearly related in the concentration range of 0.01 μM-0.9 μM with the detection limit values of 0.68 nM for FFA and 0.45 nM for MFA, respectively. The developed electrode assembly was used for the quantification of both the drug analytes in human urine samples.

Antibiotic pollution causes worldwide concern due to its more apparent consequences, namely antibiotic resistance and destruction of the environment. Extensive use of antibiotics in human and veterinary drugs releases a significant amount of toxins into the sphere of living matter, causing adverse ecological impacts. This requires the design of new analytical protocols for the effective mitigation and monitoring of hazardous pharmaceutical products to reduce the environmental burden. Therefore, we present here the hydrothermal synthesis of samarium vanadate/carbon nanofiber (SmV/CNF) composite for the determination of sulfadiazine (SFZ). The synergistic effect arising from the combination of SmV and CNF accelerates charge transfer kinetics along with the creation of more surface-active sites that benefit effective detection. The structural and compositional disclosure indicates the high purity and superior attributes of the composite material that possesses the ability to improve catalytic performance. The proposed SmV/CNF sensor exhibits important static characteristics such as wide linear response ranges, low detection limit, high sensitivity and selectivity, and increased stability. To the best of our knowledge, this is the first report on the electrochemical performance of SmV/CNF, establishing its potential application in real-time analysis of environmentally hazardous contaminants.