The effects of the crosslinking position and degree of conjugation in perylene tetraanhydride bisimide microporous polymers on fluorescence sensing performance

In this study, two fluorescence conjugated microporous polymers based on perylene tetraanhydride bisimide (DP(4)A(0) and DP(4)A(2)) were prepared via Sonogashira–Hagihara cross-coupling polymerization for the efficient detection of o-nitrophenol (o-NP). They were well characterized via FT-IR, solid state (13)C NMR, elemental analysis, and other material characterization techniques. The experiments proved that both CMPs possess high thermal and chemical stability and a porous nature with Brunauer–Emmett–Teller (BET) specific surface areas of 41.3 and 402.1 m(2) g(−1). Importantly, owing to signal amplification by the conjugated skeleton, DP(4)A(0) and DP(4)A(2) exhibit extremely high sensitivity to o-NP with K(sv) values of 1.83 × 10(4) and 1.69 × 10(4) L mol(−1) and limits of detection of 5.73 × 10(−9) and 7.36 × 10(−9) mol L(−1), respectively. The sensing performance of DP(4)A(0) and DP(4)A(2) was dependent on the position of crosslinking points and crosslinking density. Finally, super amplified quenching was considered the electron transfer mechanism and hydrogen bond interactions were also present.