Triazine Core Anchored Lanthanide Driven Soft Gels: Photo Switching Emission, Robust Anticounterfeiting, and Smart Sensor Probe for Nitroexplosive/Nitrofuran Antibiotics

Stimuli-responsive luminescent soft materials are of current interest owing to their tunable processability for encryption, sensing, and multimodal security applications. Herein, a tripodal carboxylic acid based triazine mediated linker (3,3′,3″-((1,3,5-triazine-2,4,6-triyl)­tris­(azanediyl))­tribenzoic acid) has been used to synthesize photochromic coordination driven soft gel (CSG) with Tb­(III)/Eu­(III) ions. Tuning of the stoichiometric ratios exhibited a “chameleon-like” behavior upon exposure to UV lights and led to origination of white light-emitting materials. The CSGs were applied in robust anticounterfeit applications through security ink, stamping, and painting on different surfaces under variable conditions. Along with this, terbium-based CSG was used as an optical sensor for selective detection of antibiotics (nitrofurantoin (NFT), LOD = 64.25 ppb) and nitroexplosive (2,4,6-trinitrophenol, LOD = 24.5 ppb) from an aqueous medium using photoluminescence spectroscopy. RGB-mediated smartphone-based detection for nitroexplosive and antibiotic detection in real water samples aided this as a smart sensor to emphasize the real-time applicability.