Construction of electrochemical chiral interface of C3N4/Ppy/ self-assembled polysaccharide

Abstract A simple and effective chiral selector is reported baseing on Cu2+ and β-cyclodextrin (Cu-β-CD), which can be self-assembled with sodium alginate (SA) as a chiral sensor (SA-CD). The composite of C3N4 and Ppy (C3N4/Ppy) was used as an electroactive material for the enantiomeric selection of tryptophan (Trp) by differential pulse voltammetry (DPV). The sensor was constructed by combining the advantages of polysaccharide SA-CD and C3N4/Ppy. SA-CD as a chiral selector can provide a large number of chiral sites, and C3N4/Ppy as a substrate material can improve the electrochemical signal. The results showed that the electrochemical signal of C3N4/Ppy/SA-CD modified GCE to l -Trp was higher than that to d -Trp. This was due to the low affinity of C3N4/Ppy/SA-CD modified GCE to l -Trp, which made it easier for l -Trp to penetrate the electrode modified film and reach the electrode surface, resulting in a greater peak current. UV–vis and water contact angle further proved that C3N4/Ppy/SA-CD had higher binding ability to d -Trp. In addition, the sensor had good reproducibility and stability, and can be regarded as a promising platform for chiral sensing.