| Abstract: | An integrated microfluidic device is used to derivatize, separate, and amperometrically detect amino acids and peptides in the presence of naphthalene‐2,3‐dicarboxyaldehyde (NDA). The integrated system offers a rapid (4 min) simultaneous measurements of 5 amino acids (Arg, Lys, Gly, Cys, PhenA) down to the 3.2 μM level in connection to a precolumn reaction chamber, an electrophoretic separation channel, and an end‐column thick‐film carbon‐electrode detector. The effect of the separation voltage, detection potential, reagent concentration, and other variables on the response is examined. Calibration and precision experiments indicate a linear and reproducible response. Applicability for the separation and detection of small peptides is demonstrated. Such on‐chip generation of electroactive products offers great promise for detecting other nonelectroactive analytes. |
