Two robust Zn-CPs as multiresponsive turn-on fluorescent sensors for the detection of five quinolone antibiotics

Effective detection of quinolone antibiotic residues has garnered significant concern due to their potential health risks and adverse effects on animal and human health. Herein, two robust zinc(II) coordination polymers (CPs), {[Zn 2 (L)(DCTP) 2 ]·H 2 O} n ( 1 ) and {[Zn 2 (L)(MIP) 2 ]} n ( 2 ) ( L = bis(1-(pyridin-4-ylmethyl)-benzimidazol-2-ylmethyl)ether, H 2 DCTP = 2,5-dichloroterephthalic acid, H 2 MIP = 5-methylisophthalic acid), were prepared by solvothermal reaction. 1 features a (3,4,4)-connected framework, and 2 exhibits a (3,4)-connected network. These two CPs as turn-on fluorescence sensors could display effective detecting abilities for five quinolone antibiotics (pefloxacin (PEF), enrofloxacin (ENR), ciprofloxacin (CIP), levofloxacin (LEV), and norfloxacin (NOR)) with naked-eye recognition. The concentration ranges of different analytes sensed by 1 and 2 with good linearity response were 0 − 4.75 and 0 − 6.50 µmol· L −1 for PEF, 0 − 14.00 and 0 − 11.00 µmol· L −1 for ENR, 0 − 10.75 and 0 − 17.50 µmol· L −1 for CIP, 0 − 5.75 and 0 − 11.00 µmol· L −1 for LEV, and 0 − 5.25 and 0 − 94.00 µmol· L −1 for NOR, respectively. Notably, the limits of detection for LEV were exceptionally low, at 2.47 × 10 −9 mol· L −1 for 1 and 1.22 × 10 −8 mol· L −1 for 2. Moreover, CPs have strong recyclable ability, excellent selectivity, and anti-interference ability. The fluorescence sensing mechanism of 1 and 2 was investigated in detail.