Amperometric biosensors for L-alanine and pyruvate assays in biological fluids

Two amperometric electrochemical biosensors have been developed and used to determine the concentrations of L-alanine and pyruvate in biological fluids (blood, fermentation media) without any prior treatment of the sample. The proposed biosensors have response times lower than 5 min, a precision of 2% and the measured current is proportional to the substrate concentration in the range from 1×10−6 to 2×10−3 mol l−1. They have an operating life of one month.