Fabricating a mechanochromic AIE luminogen into a wearable sensor for volatile organic compound (VOC) detection

Solid-supported sensors and devices benefit greatly from aggregation-induced emission (AIE) molecular systems, on account of their high emission efficiency in the aggregated state. In this study, we present an AIE luminogen, (E)-1-(((4-acetylphenyl)iminio)methyl)naphthalen-2-olate (AINO), decorated with electron donor-acceptor (D-A) units. It has strong emission at solid state, but undergoes sharp decrease accompanied by slight hypochromatic shift in response to mechanical stimuli. After fumigation with volatile organic compound (VOC), the emission intensity recovers, showing reversible mechanochromic luminescence. Crystal analysis reveals its working mechanism, which is generally ascribed to the formation of coupled π-dimers. Based on the vapochromic recovery of the mechanochromic luminescence; a wearable impregnated cellulose sensor is fabricated, capable of being encapsulated into clothes and gloves. It exhibits remarkable emission change with high visual discrimination when exposed to VOC, affording a low detection down to 17.40 ± 6.91 mg/m3 (4.16 ± 1.77 ppm).