Electroactive Flexible Sensor for Selective L-Ascorbic Acid Detection Using Polyaniline-Decorated Phosphotungstic Acid/Copper Composite

In this letter, we spotlight a flexible stainless steel (FSS)-based hybrid electrode with phosphotungstic acid-copper-embedded poly (aniline) (FSS/PANI/PTA/Cu) composite for the efficient detection of L-ascorbic acid (AA). Single pot electrodeposition has been engaged in fabricating PANI/PTA/Cu composite on FSS via cyclic voltammetry (CV). The successful composite fabrication has been authenticated through physicochemical characterization, including its structural geometry, surface morphology, and molecular vibrational properties, which were analyzed through X-ray crystallography, field emission scanning electron microscopy, infrared spectroscopy and UV-Vis spectrophotometers. The electrochemical sensing performances were examined using CV and chronoamperometric analysis. The flexible sensor measured a sensitivity of 3.79 mA/mM with a detection limit of 7.9 µM for AA. This performance results from the combined synergetic action of PANI, PTA, and Cu, which enabled efficient ionic diffusion and seamless electron transfer through a high density of accessible electroactive sites. In addition, the flexible sensor electrode exhibited remarkable selectivity for AA, with negligible interference from coexisting species, highlighting its potential for healthcare diagnostic applications in near future.