Direct Identification of Tryptophan in a Mixture of Amino Acids by the Naked Eye

Electrochemical Sensors for L-Tryptophan Based on Molecularly Imprinted Polymers

A novel sensing element for direct detection of L-Tryptophan (L-Trp) in human serum was proposed by combination of electrochemical transduction and molecular imprinting technique. The sensing element was prepared by electropolymerization of o-phenylenediamine (o-PD) on the gold electrode in the presence of template L-Trp. The electrochemical property of the sensor was characterized by differential pulse voltammetry (DPV). The linear response range of the sensor for L-Trp concentration was 1×10-8 mol/L~21×10-8 mol/L with a detection limit of 0.3×10-8 mol/L. The results show that this approach has the potential to generate a universal inexpensive assay methodology of high sensitivity, specificity and simplicity to detect L-Trp.