Molecularly Imprinted Polymers Based on Cyclodextrin Derivatives and Chitosan for Selective Extraction of Analytes

A series of molecularly imprinted polymers (MIPs) based on hydroxypropyl-β-cyclodextrin (HPCD) crosslinked with 1,6-hexamethylene diisocyanate (HMD) or toluene diisocyanate (TDI), as well as hybrid chitosan–HPCD polymers crosslinked with genipin, were synthesized using levofloxacin and fluorescein as template molecules. The structure and spatial organization of the obtained materials were characterized by FTIR spectroscopy, FTIR microscopy mapping, and ζ-potential measurements. The influence of pH, crosslinker content, and template structure on sorption performance was investigated. All MIPs exhibited maximum sorption at pH 3.0. The highest sorption capacity toward levofloxacin was achieved for the Chit–HPCD–G polymer (74.8 mg/g), whereas the fluorescein-imprinted HPCD–TDI (1:1) MIP demonstrated the highest sorption capacity (135.5 mg/g) and selectivity coefficient (84.1). Dynamic column experiments con-firmed efficient analyte extraction, reducing the analyte concentration by more than 90% after ten loading cycles. All synthesized MIPs exhibited excellent regenerability, with less than 3% loss of sorption efficiency after ten consecutive sorption–desorption cycles. The applicability of the developed sorbents to real matrices was demonstrated using milk and blood plasma samples after minimal sample preparation. Fluorescein extraction efficiencies reached 97.6% and 93.6% for milk and plasma, respectively. The obtained results demonstrate that HPCD-based MIPs combine high sorption capacity, exceptional selectivity, operational stability, and applicability to complex biological matrices, making them promising materials for selective sample preparation, analyte pre-concentration, and controlled drug delivery systems.