Molecular‐To‐Device Integration: A Turn‐On Polymeric Receptor for IoT‐Enabled Detection of Explosive TKX‐50
Somnath Bej, Aniket Balapure, Sourav Dutta, Deepak K S, P. Ramya Priya, Nripen Khilari, Debmalya Roy, Satish Kumar Dubey, Samit Chattopadhyay, Debasis Koley, Sumit Kumar Pramanik, Sanket Goel, Amitava DasABSTRACT
The rational design of responsive molecular frameworks that convert molecular recognition into measurable optical signals is crucial for advanced sensing technologies. Herein, we report a preorganized 3D conjugated polymeric receptor integrated with a custom‐built IoT‐enabled photonic platform for the quantitative detection of the advanced explosive TKX‐50. The polymeric receptor ( 2 ), synthesized from tris(4‐aminophenyl)amine (TAPA) and tetraphenylethylene (TPE) motifs, exhibits a selective fluorescence “turn‐on” response toward TKX‐50. Structural and spectroscopic analyses confirm the formation of a thermally robust imine‐linked polymeric framework with spherical morphology. Receptor 2 shows a broad emission band with λ max ∼600 nm ( Φ Ems = 0.005, Ru(2,2′‐bipy) 3 2+ as reference), whereas TKX‐50 binding induces a strong emission at ∼ 475 nm (Φ Ems = 0.51, Ru(2,2′‐bipy) 3 2+ as reference), affording an ultralow detection limit of 29.2 nM. Time‐resolved fluorescence and DFT/TD‐DFT studies reveal that hydrogen bonding‐driven charge transfer and excited‐state rigidification suppress nonradiative decay pathways associated with phenyl‐ring rotation. This emission response was utilised for photocurrent generation and the development of a portable IoT‐integrated fluorometric device. A custom‐made LED‐photodiode architecture enables rapid, reproducible, and quantitative detection of TKX‐50. This work integrates purpose‐built polymer design with intelligent optoelectronic engineering, establishing a new paradigm for real‐time, field‐ready detection of energetic materials.