Biosensors for the enantioselective analysis of pipecolic acid

Mono- and bienzyme-based amperometric biosensors were used for the direct enantioanalysis of l- and d-pipecolic acid in serum samples. The biosensors were designed using physical immobilization of l-amino acid oxidase and/or horseradish peroxidase for the assay of l-pipecolic acid, and d-amino acid oxidase and horseradish peroxidase for the assay of d-pipecolic acid. Electrode characteristics were obtained and compared for the different carbon paste biosensors at different working potentials. The linear concentration ranges for the proposed biosensors were in the fmol/l to μmol/l magnitude order with limits of detection of fmol/l to pmol/l magnitude order. The results obtained for enantioanalysis of l- and d-pipecolic acid in serum samples are correlating very good with those obtained using a standard method of analysis.