Blueprinted from nature: Duplicating the surface of Xanthosoma sagittifolium leaf on UV-curable electroactive polymethacrylate film through biomimicking technique for H2S gas sensing

Abstract

This research introduces an innovative methodology for developing an H2S gas sensor utilizing bio-templated electroactive polymethacrylate (Bio-EPMA), achieved by integrating efficient and economical UV-curing technology with biomimicking. Drawing inspiration from the intricate surface structure of natural Xanthosoma sagittifolium leaves, the biomimetic template employed during synthesis is pivotal to this groundbreaking approach. Starting from the electroactive component, aniline tetramer (AT) was synthesized via an oxidative coupling reaction. Concurrently, the UV-cured monomer glycidyl methacrylate (GMA) underwent photopolymerization to form poly-GMA, which subsequently underwent an epoxide ring-opening reaction with the amino group of AT to yield EPMA. This base polymer was then meticulously tailored to feature a biomimetic surface morphology through the biomimicking technique, resulting in Bio-EPMA formation. Comprehensive analysis of the Bio-EPMA films showed remarkable hill microstructures and nanowrinkled surface morphology, with an enhancement of BET surface area from 5.7 m²/g to 20.4 m²/g and a 1.15-fold increase in reversible doping capacities. Following film fabrication, interdigitated electrode (IDE) sensors were coated with the synthesized biomimetic films for H₂S gas sensing evaluations. Remarkably, the Bio-EPMA film demonstrated superior performance compared to non-biomimetic controls. This amplified performance is attributed to the increased surface area and bio-inspired structure of the Bio-EPMA film, which remarkably resulted in significant enhancements in responsivity by 36.2 % and repeatability with a relative standard deviation (RSD) improvement from 20.11 % to 3.62 %.