A [Co5] cluster‐based organic framework as fluorescent detection platform toward quinolone antibiotics

The detection of quinolone antibiotics is an important research hotspot for protecting human health. Herein, a three‐dimensional metal–organic framework with the formula of {[Co5(TPT)2(BPDC)3(μ3‐O)2(H2O)4]·8MeCN·3DMF}n (NS‐3, TPT = tris(4‐pyridyl)‐1,3,5‐triazin, H2BPDC = 1,4‐benzenedicarboxylic acid) has been successfully prepared through solvothermal method. Single‐crystal X‐ray diffraction analysis revealed that three‐dimensional NS‐3 can be viewed as an eight‐connected sqc4 net with pentanuclear [Co5(μ3‐O)2]6+ cluster as metal nodes. Importantly, when norfloxacin, ofloxacin, and enrofloxacin were added in NS‐3 ethanol suspension, the luminescence intensity of NS‐3 at 333 nm was obviously decreased while new emission peaks clearly emerged, indicating that NS‐3 can be a potential rare fluorescent detection to recognize quinolone antibiotics in ethanol. Additionally, NS‐3 exhibits high sensitivity to norfloxacin, ofloxacin, and enrofloxacin with a limit of detection of 43, 34, and 139 nM, respectively, which is superior to most of the reported metal–organic frameworks. A pentanuclear cobalt‐based organic framework with high sensitivity toward quinolone antibiotics has been synthesized and characterized in detail.