Electrochemical Recognition of Tyrosine Enantiomers Based on Chiral Ligand Exchange with Sodium Alginate as the Chiral Selector

Enantiorecognition of tyrosine (Tyr) enantiomers is realized via chiral ligand exchange technology combined with electrochemistry. A natural polymer, sodium alginate (SA), is electrodeposited on a glassy carbon electrode (GCE) and adopted as the chiral selector to form a diastereoisomeric ternary complex of [(SA)Zn(II)(L-Tyr)] or [(SA)Zn(II)(D-Tyr)] in the presence of Zn(II). Due to the difference in steric hindrance during the formation of these two complexes, the chiral selector preferentially recognizes D-Tyr. The electrochemical enantiorecognition of Tyr enantiomers is characterized by cyclic voltammetry and electrochemical impedance spectroscopy (EIS), and the parameters affecting the recognition efficiency are also investigated.