Novel Boronate Affinity Molecularly Imprinted Nanomaterials for Selective Dispersive Magnetic Solid-Phase Extraction of Catecholamines from Equine Urine

• Novel dual-affinity magnetic nanosorbent : Developed catechol-imprinted magnetic molecularly imprinted polymers (Ca-DFFPBA-MMIPs) via a pioneering two-step template immobilization protocol that synergistically integrates boronate affinity with surface molecular imprinting, enabling selective recognition of catecholamines under neutral pH conditions (pH 6.5-7.0) without analyte degradation. • Exceptional selectivity and reusability : The optimized nanomaterial demonstrated outstanding molecular recognition with high imprinting factors (IF = 7.1-10.5) for target catecholamines, and maintained ≥90% of initial adsorption capacity after seven consecutive extraction cycles, ensuring robustness and cost-effectiveness for routine analysis. • Sensitive analytical performance for doping control : Achieved low limits of detection (12-31 ng mL⁻¹) and quantification (40-103 ng mL⁻¹) with excellent precision (intra-day RSD ≤1.13%, inter-day RSD ≤1.95%), successfully applied to selective extraction of prohibited catecholamines from equine urine with recoveries of 64.5-105.7%. • Innovative design overcoming conventional limitations : Utilized catechol as a dummy template to eliminate template leakage issues, while electron-withdrawing DFFPBA ligands provided high cis-diol affinity at physiological pH, representing a paradigm shift for selective enrichment of labile biomarkers in complex biological matrices. In this study, we developed catechol-imprinted magnetic molecularly imprinted polymers (Ca-DFFPBA-MMIPs) via a dual-affinity strategy combining boronate affinity and a two-step template immobilization protocol. The Ca-DFFPBA-MMIPs exhibited high affinity and selectivity for catecholamines (norepinephrine, epinephrine, and dopamine) under neutral conditions. The adsorption capacity reached a plateau at pH 6.5-7.0, and the adsorption time was optimized to 40 minutes. The MMIPs showed excellent selectivity for the target catecholamines over structurally related interferents. The Ca-DFFPBA-MMIPs also demonstrated good reusability, retaining ≥90% of their initial adsorption capacity after seven consecutive cycles. The analytical performance of the Ca-DFFPBA-MMIPs was validated in terms of linear range, coefficient of determination (R²), limit of detection (LOD), limit of quantification (LOQ), and intra- and inter-day precision (RSD). The LODs were 12-31 ng mL⁻¹ and LOQs were 40-103 ng mL⁻¹, with RSDs of 0.87-1.13% (intra-day) and 1.75-1.95% (inter-day). The Ca-DFFPBA-MMIPs were successfully applied to the selective extraction of catecholamines from equine urine (enrichment factors of 18-27), with recoveries ranging from 64.5% to 105.7%. This study provides a new approach for the analysis of catecholamines in complex matrices and highlights the potential of Ca-DFFPBA-MMIPs as a practical nanosorbent for efficient and selective enrichment of catecholamines and related compounds.