Chiral l -histidine-ZIF-8/MWCNTs-based molecularly imprinted electrochemical sensor for l -tryptophan

-phenylenediamine in the presence of β-cyclodextrin and L-Trp. After removing the template, "imprinted cavities" with specific recognition capabilities were formed, thereby enabling the selective detection of L-Trp. Under optimized conditions, the sensor exhibited a wide linear response from 1 nM to 1 mM with a detection limit of 0.34 nM, together with good selectivity, reproducibility, and stability. The sensor was further applied to L-Trp determination in milk samples with satisfactory recoveries, demonstrating its potential for the analysis of chiral amino acids in complex samples.