Tetramethylbenzidine loaded PVA nanofibers strip for visual detection of hydrogen peroxide via Cu2+ catalysis and its applications

BACKGROUND: Advancements in sensor technology have facilitated the development of cost-effective and highly sensitive sensors which have significantly improved the detection of biological analytes in various fields. This study presents a novel approach for the detection of hydrogen peroxide (H₂O₂), a critical analyte in both biological and environmental systems. A simple and sensitive colorimetric sensing platform was developed based on polyvinyl alcohol (PVA) nanofibers loaded with tetramethylbenzidine (TMB). RESULTS: The nanofibers were characterized using scanning electron microscopy, confirming the formation of smooth, spindle-shaped fibers with diameters from 324 to 551 nm. The colorimetric detection method utilized TMB, which undergoes oxidation in the presence of H2O2 catalyzed by Cu2 + resulting in the formation of a characteristic blue color. It revealed a linear increase in absorbance corresponding to H2O2 concentrations from 3.125 to 100 µM, with a low detection limit of 2.60 µM. The system exhibited excellent specificity and selectivity for H₂O₂ with a visual color gradient scale over common biological interferents such as glutathione, L-cysteine, urea, ascorbic acid, or various ions at a concentration of 100 µM. The new colorimetric sensor was successfully used to determine the H2O2 level in human urine from healthy subjects demonstrated excellent recovery rates (96–103%). SIGNIFICANCE: This work introduces a simple, cost-effective, and highly selective colorimetric sensor, which is capable of rapid, on-site H₂O₂ detection without reliance on complex instrumentation. Also, the electrospun PVA/TMB exhibits strong potential of nanofibers to be used as a valuable tool for medical diagnostics, environmental monitoring and other biosensing applications.