Highly sensitive and rapid fluorescence detection of chlortetracycline in milk using a water- and pH-stable Zn (II) coordination polymer derived from zwitterionic and N-donor ligands

A novel and interesting Zn (II) coordination polymer, [ZnL(4,4'-bpd)(H2O)(2)]center dot(ClO4)(2) (CP 1), was synthesized under hydrothermal conditions by a zwitterionic organic ligand (1,1'-((2,5-dimethyl-1,4-phenylene)bis(methylene))bis(4-carboxypyridin-1-ium)chloride (H2LCl2)) and a N-donor ligand (4,4'-bipyridine (4,4'-bpd)). Fluorescence sensing experiments showed that CP 1 preforms high selectively and sensitivity for rapid detection of Chlortetracycline (CTC) in aqueous solutions via fluorescence quenching effects and has a shallow detection limit (0.015 mu M). In addition, The CP 1 is the first example of a fluorescent sensor that can sensitively detect CTC in milk with a perfect recovery rate of 92.97 -103.83%. The possible mechanism of the fluorescence quenching mechanisms of the CP 1 was described as internal filtration effect (IFE) and photoelectron electron transfer (PET).

Automated summary

A novel Zn(II) coordination polymer was synthesized and showed high selectivity and sensitivity for rapid detection of chlortetracycline via fluorescence quenching effects. It also demonstrated the ability to detect chlortetracycline in milk with a high recovery rate.