Constructing electrochemical sensor using molecular-imprinted polysaccharide for rapid identification and determination of l-tryptophan in diet

•The selective recognition of the MIPs, the chiral sites of chitosan and signal amplification of MWCNTs were synergistic.•The MIPs layer was prepared with o-phenylenediamine and β-cyclodextrin as bifunctional monomers.•The sensor effectively distinguished the enantiomers of tryptophan.•The sensor could avoid the chiral effect of amino acids affecting the detection of l-tryptophan.•The sensor could predict the proportion of l-tryptophan in the mixture of tryptophan enantiomers.