Aggregation-induced emission-active hyperbranched polymers conjugated with tetraphenylethylene for nitroaromatic explosive detection.

This work develops a facile synthesis for aggregation-induced emission (AIE)-active hyperbranched polyglycidols (HPGs) to design a solid-state sensor for detecting nitroaromatic explosives. The tetraphenylethylene moieties were conjugated onto the periphery of the HPGs in a single step using dynamic boronate ester cross-linkers. The resulting AIE-active HPGs exhibited excellent AIE characteristics in tetrahydrofuran (THF)/H 2 O mixtures, emitting a strong blue fluorescence under UV irradiation. Dynamic light scattering and transmission electron microscopic analyses demonstrated that the self-assembled nanosized aggregates were stable in the THF/H 2 O mixture. The fluorescence of the aggregates was dramatically quenched by various nitro compounds, including 2,4,6-trinitrophenol (or picric acid; PA), 2,6-dinitrophenol, 4-nitrophenol, 4-nitrotoluene, and nitromethane. The nano-aggregates exhibited extraordinary sensitivity towards PA, with a Stern‒Volmer constant (K sv) of 2.27 × 104 M−1 and a limit of detection of 40 ppb. Paper strips encapsulating the aggregates exhibited a vivid visual quenching, promising the practical applicability of these polymers as solid-state sensors for the detection of nitroaromatic explosives. [Display omitted] [ABSTRACT FROM AUTHOR]