Efficient smart-phone luminescent sensing detection based on new multifunctional Cd(II) luminescent coordination polymers.

Based on the mixed ligand strategy, two new isostructural Cd coordination polymers: {[Cd(tcpa)(bima)(DMF)]‧3DMF} (CP 1), {[Cd(tcpa)(bmima)(DMF)]‧3DMF} (CP 2) were synthesized by combining two flexible anthracene-based and a triphenylamine-based ligands with large π-electron-rich structure using a solvothermal method (Htcpa = tris(4-carboxyphenyl)amine; bima = 9,10-bis(1H-imidazole-1-yl)methyl)anthracene and bmima = 9,10-bis((2-methyl-1H-imidazol-1-yl)methyl)anthracene). CP 1 and CP 2 show an unreported new 3D (3,14)-c net structure with the {4·6·8}{4} topology. Both CPs could detect CrO, Nitroaromatic explosives 2,4,6-Trinitrophenol (TNP) and 2,4-dinitrophenol (DNP) through rapid fluorescence quenching response with high quenching efficiency Ksv and low LOD with 0.19 μM (CrO), 0.54 μM (TNP), 0.76 μM (DNP) for CP 1 and 0.28 μM (CrO), 0.23 μM (TNP), 0.65 μM (DNP) for CP 2, respectively. In addition, the mechanism of quenching CrO, TNP and DNP by CPs is proposed through experimental research and theoretical simulation. The quenching of CrO by CPs is mainly competitive absorption (CA), while the quenching of TNP/DNP is achieved through the coexistence of competitive absorption CA, photo induced electron transfer (PET) and fluorescence resonance energy transfer (FRET). Moreover, we have been developed a portable smartphone-assisted on-site detection platform, which can perform semi-quantitative analysis of CrO acconding to fluorescence color changes. This work constructed a ratiometric sensing platform for quickly and conveniently detection of CrO, TNP and DNP pollutants.