Highly enantioselective recognition of various acids using polymerized chiral ionic liquid as electrode modifies

It is desirable to develop an approach for highly enantioselective recognition by using electrochemical analysis. Here, a novel chiral poly(ionic liquid)-metal complex ( S , S )-PCIL-5-Cu(II), derived from (1 S ,2 S )-1,2-diphenyl-1,2-ethanediamine, is synthesized through the multi-step route. Combined with the polymer bearing the electroactive unit, an electrochemical chiral sensor is constructed by using ( S , S )-PCIL-5-Cu(II) as modification on the electrode surface for the first time. It is observed that the electrochemical sensor is successfully applied to chiral recognition of various acids by comparing signals including the peak current ( I P ) and the oxidation peak potential ( E P ). Specifically, L or ( S ) forms exhibit higher I P compared to D or ( R ) forms. For example, the peak current ratio ( I L / I D ) for malic acid is 24.8. Meanwhile, E P of D -malic acid is located negatively versus L -malic acid with the separation difference of 88 mV. Additionally, a good linear relationship between the ee value and I P is achieved. In brief, our results highlight the feasibility of the proposed approach for electrochemical chiral recognition and ee determination, which can further advance the feasibility of the functional poly(ionic liquid).