Dynamic Color-Tunable Photonic Crystal Films for Visual Detection of Gasoline Vapor and Arduino-Assisted Concentration Quantification

Gasoline leaks and explosions pose a significant global safety concern. Since the primary components of gasoline consist of various alkanes, underscoring a critical need to develop advanced smart sensing technologies for accurate and real-time detection of atmospheric gasoline concentrations. In this study, simple photonic crystals (PCs) were developed by integrating isoprene-N,N′-methylenebis(acrylamide) copolymer (P(IP-MBA)) with mesoporous TiO2 for visual quantitative determination. Based on the principle that swelling is more likely to occur when the Hansen solubility parameters of the polymer and that of the solvent are similar, the polymer exhibits greater swelling in the presence of alkanes in gasoline, displaying distinct colors at different concentrations across the entire visible spectrum. Within the explosion limit of gasoline, the PCs exhibit a color shift from violet to red, with a detection limit of approximately 750 ppm. For the first time, an Arduino processor has been integrated into photonic crystal detection by designing and assembling a color analysis system, enabling the quantitative display of concentration information. By utilizing a color recognition module to capture the RGB signal changes from the photonic crystal, the Arduino Uno processes and outputs the data to the TM1638 Digital LED Display Module (TM1638), which then displays the gasoline concentration as a ppm value. This system could potentially be used for future explosion hazard warnings.