Hybrid imprinted membranes for selective recognition of quercetin

• Hybrid imprinted membranes for specific recognition of quercetin were developed.
• Quercetin-imprinted membranes showed high binding capacity.
• The second order kinetic and Langmuir models fit well the experimental data.

Hybrid imprinted membranes exhibiting specific recognition properties towards the quercetin (the template) were developed. In this perspective, an imprinted copolymer of acrylonitrile, using acrylamide as functional co-monomer was synthesized. For comparison, a non-imprinted polymer was also prepared. Various membranes were produced by dispersing different copolymer amounts in a poly(ether ether ketone) (PEEK-WC) matrix. Scanning Electron Microscopy, and Fourier Transform Infrared analysis confirmed the presence of the polymer into the hybrid system. Membrane permeability was in the ultrafiltration range (70–180 l/h m2 bar). The addition of polymer to the support membrane determined a slight decrease of the membrane hydrophobicity. The solvent uptake degree was very low (between 1.2% and 1.32%), suggesting a weak interaction between the polymer and the binding solvent. No significant change in the mechanical properties were observed.The membranes recognized the quercetin in different extend. The highest imprinting factor (3.6) and binding capacity (12.0 mol/gmemb.) was exhibited by the membranes containing the 25 wt.% of the imprinted polymer (PEEK-WC/25% MIP). This membrane was also selective vs chrysin and naringin, (structural homologs of quercetin). The selectivity factor quercetin/naringin was 4.5 and that one of the couple quercetin/chrysin was 1.8.The Langmuir adsorption model was suitable for correlation of equilibrium data. The kinetic of quercetin adsorption of PEEK-WC 25% MIP membrane was efficiently predicted by the second-order model.