Thienothiophene based AIE-Active bulky materials for sensitive explosive detection

Sensors for selective and sensitive detection of nitroaromatic (NAC) explosives are of current interest for both national security and environmental protection. In this work, three thienothiophene based AIE active materials (TPE2-TT, TPE3-TT and TPE3-TPA-TT), possessing tetraphenylethylene and triphenylamine units, were designed and synthesized as chemosensors for sensitively detecting 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT) and trinitrophenol (TNP) explosives. Among the AIEgens, TPE3-TT demonstrated a maximum Stern-Volmer constant (K_sv) reaching to 2.9 x 10⁴ M⁻¹ by quenching response toward TNP. They exhibited vivid visual quenching on absorbent papers. Moreover, probe-explosive complex interactions and their mechanisms were investigated using density functional theory (DFT). Their remarkable properties indicated that TT based AIEgens are promising probes for sensitively detecting the explosives, which provided a new source of potential leading to new designs for detection of explosives.