The preparation of hexaphenylsilole-based conjugated microporous polymer for fluorescence sensing o-nitrophenol

A first hexaphenylsilole-based conjugated microporous polymer, termed THPS, was prepared by a Friedel-Crafts arylation reaction of 1,1,2,3,4,5-hexabenylthirole with 2,4,6-trichloro-1,3,5-triazine catalyzed by anhydrous aluminium trichloride (AlCl₃) in 1,2-dichloroethane. Its Brunauer-Emmett-Teller and Langmuir surface area reached up to 1579 and 2081 m² g^-1, and total pore volume and micropore pore volume were severally 0.8325 and 0.7322 cm³ g^-1. THPS could fluorescence-sense o-nitrophenol with high sensitivity and selectivity. Its fluorescence quenching constant (K_SV) and limits of detection (LODs) were severally 8.32 × 10³ L mol^-1 and 3.61 × 10^-10 mol L^-1. The fluorescence quenching of THPS by o-nitrophenol was originated from the combined action of both photo-induced electron transfer mechanism and resonance energy transfer mechanism.