A molecular imprinting-based multifunctional chemosensor for phthalate esters

This paper reports a molecular imprinting-based fluorescent and solvatochromic multifunctional chemosensor for phthalate esters (PAEs). The multifunctional chemosensor was fabricated through precipitation polymerization using 4-[(1E)-4-(2-hydroxyphenyl) ethenyl]-1-allylpyridinium bromide (HPEAPB) as the functional monomer and phthalamide-4,4'-dibutyl dimethyl ester (PDDB) as the mimic template. The molecular imprinting-based chemosensor shows specific affinity toward PDDB and dibutyl phthalate (DBP) in ethanol. Of note is that the molecular imprinting-based chemosensor shows turn-off fluorescent response toward PAEs in an ethanol solution with a limit of detection of 2.0 × 10⁻⁶ mol L^-1 (0.7 ppm) when HPEAPB is in the protonated form (chemosensor 1), and shows solvatochromic properties, fluorescent enhancement and a colorimetric (from orange to bright yellow) response toward PAEs in an ethanol solution with a limit of detection of 4.0 × 10⁻⁵ mol L^-1 by the naked eye when HPEAPB is in the deprotonated form (chemosensor 2). This multifunctional chemosensor is promising for the simple, accurate and low-cost detection of trace PAEs.