Design of chiral acidic molecularly imprinted polymer for the enantioselective separation of (±)‐DOPA

Background The study focuses on developing a stable enantioselective matrix for the efficient chiral identification and enantioresolution of l ‐DOPA and (±)‐DOPA. The matrix is derived from a copolymeric material made from poly[(vinylsulfonic acid)‐ co ‐(4‐vinylpyridine)] crosslinked with divinylbenzene. Results l ‐DOPA‐vinylsulfonamide was synthesized and characterized. This chiral sulfonamide was copolymerized with 4‐vinylpyridine in the presence of a divinylbenzene crosslinker, using azobisisobutyronitrile as a thermal initiator. Post‐polymerization, the polymeric particles were treated with NaOH and subsequently washed with acid to remove the integrated l ‐DOPA species. Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed the imprinted l ‐DOPA‐IP particles. The manufactured l ‐DOPA‐IP demonstrated a tenfold greater affinity for l ‐DOPA compared to d ‐DOPA. Langmuir adsorption experiments at pH 6 showed a maximum capacity of 162 mg g −1 . Enantiomeric excess values for l ‐ and d ‐DOPA, determined through optical separation using a column approach, were 94% and 82%, respectively, in the loading and recovery solutions. Conclusion The developed copolymeric material effectively served as an enantioselective matrix, exhibiting high selectivity and capacity for l ‐DOPA. The process demonstrated efficient chiral identification and separation, achieving significant enantiomeric excess values for both l ‐ and d ‐DOPA.