Synthesis of conjugated microporous polymer-based fluorescent “turn-off” sensor for selective detection of picric acid

Abstract

Various structures of conjugated microporous polymers (CMPs) were synthesized via the Suzuki cross-coupling reaction to detect the explosive compound, picric acid (PA). One of the CMP, CMP-3 showed high fluorescence in the solid state because of the presence of repeat unit with aggregation-induced emission (AIE). Upon exposure to PA, the fluorescence of CMP-3 was noticeably quenched (190.10-fold) compared to other CMPs. The addition of other nitroaromatic compounds such as 2,4-dinitrotoluene (2,4-DNT) or 2,6-dinitrotoluene(2,6-DNT), which were similar in structure to PA, did not affect the fluorescence of CMP-3, indicative high selectivity of the sensing material.