Cationic conjugated microporous polymers for efficient quinolone antibiotics extraction: Experimental and DFT study

The development of exquisitely sensitive analytical methods for the surveillance of quinolone antibiotics (QAs) holds pivotal significance in safeguarding both ecosystems and human well-being. In this work, a cationic conjugated microporous polymer (iCMP) was constructed through a facile post-synthetic approach. Capitalizing on its unique dual-porosity architecture, cationic framework, and π-conjugated backbone, iCMP exhibited exceptional adsorption capabilities and remarkable repeatability. Integrating with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a solid-phase extraction (SPE) method founded on iCMP was meticulously developed for the sensitive and accurate detection of QAs within complex matrices. This proposed analytical method exhibited remarkably low limits of detection, specifically 0.0200-0.128 ng·L^-1 for water samples and 0.0250-0.105 ng·g^-1 for meat samples, along with good accuracy in the range of 70.9 %-115 %. The underlying adsorption mechanism was comprehensively investigated using a synergistic approach that combined systematic adsorption experiments, density functional theory (DFT) calculations, and in-depth material characterizations. Overall, this study presents viable strategies for the precise trace-level analysis of QAs in complex environmental and food samples.