Electrochemical Sensor for Tryptophan Determination Based on Copper-cobalt Hexacyanoferrate Film Modified Graphite Electrode

In this work, the development of a tryptophan sensor and its application to milkare described. The mixed metal (copper and cobalt) hexacynoferrates are electrodepositedon the graphite electrode, and this film exhibits an electrocatalytic activity towards for theoxidation of tryptophan. The experimental conditions, including the scan cycles, the ratio ofcopper(II) and cobalt(II), pH value, applied potential, are investigated in detail. At theoptimal conditions, the eletctrocatalytic response is a linear relationship with theconcentration of tryptophan in the range of 10 μM and 900 μM, with a detection limit ofabout 6 μM. This modified electrode was also successfully used to detect the tryptophanconcentration in milk.