A Zinc Coordination Polymer Sensor for Selective and Sensitive Detection of Doxycycline Based on Fluorescence Enhancement

In this work, a novel coordination polymer HNU-55 has been synthesized by the reaction of Zn(II) ion with the organic ligand 3-pyridinesulfonic acid (PSA) under solvothermal condition, which can be used as a fluorescent sensor for the detection of doxycycline (DOX). The fluorescent performance is effective in a wide linear range from 0 to 30 μM of DOX with a low detection limit of 3.7 nM. Likewise, the fluorescent sensor presents good selectivity, anti-interference, and circularity. Additionally, the HNU-55 sensor can be successfully used to assay the content of DOX in pig feed. Furthermore, the mechanism of fluorescence enhancement has been discussed in detail, which provides a clear understanding for the antibiotic detection based on the fluorescence enhancement.