Regulating the wetting behaviors of hollow silica photonic crystals in detection and encryption applications

Abstract

Regulating the wettability of photonic crystals (PCs) could manipulate the liquid flow, and thus, multiple response patterns were realized for information storage and sensing devices. In this paper, to realize solvent detection by response patterns with shapes and colors difference, several modified agents were introduced into hollow silica photonic crystals (HSPCs), obtaining the array sensors. The as-prepared array sensors exhibited superior sensitivity and wide detection range for organic solvents, which showed six response patterns in response to different organic solvents wiping due to surface tensions and reflective index difference of solvents. The array sensors could verify cyclohexane and N-hexane by their surface tensions differences, and verify the diiodomethane by reflective index difference with an 83 nm of reflection wavelength shift. Furthermore, information encryption and multilevel decryption were realized on modified HSPCs, different encrypted patterns and words would be revealed by ethanol solutions (5% and 15% concentration) wiping. Overall, based on the above-mentioned properties, this strategy by regulating wetting behaviours of HSPCs would pave a new route for self-reporting sensors fabrication and complex information encryption.