Ultrasensitive fluorescence detection of norfloxacin in aqueous medium employing a 2D Zn(ii)-based coordination polymer

Abstract

A mixed-ligand ternary Zn(II) coordination polymer (CP), {[Zn(L)_0.5(mip)] 1.75H₂O}_n (1) (L = 1,4-bis(thiabendazol-1-ylmethyl)benzene, H₂mip = 5-methylisophthalic acid), was prepared and characterized. 1 features a 2D hcb layer, which can further expand into a 3D supramolecular framework via weak hydrogen bonding interactions. 1 exhibits excellent chemical stability and pH tolerance. Importantly, 1 is the first fluorescent probe based on CPs to detect norfloxacin (NOR) with a 30 s response and an ultra-low detection limit (0.159 nmol L⁻¹). Further, the fluorescence sensing mechanism of 1 may be attributed to the combination of electron and energy transfers from CP particles to NOR molecules.