Effect of the geometry of microfabricated flow reactors on chemiluminescent detection of epinephrine with lucigenin

Abstract
Three types of flow reactors with different lengths (12–126 mm) and widths (0.4–2.0 mm) of channel were made on the silicon chip by microfabrication techniques for the chemiluminescent (CL) detection of epinephrine (EP) with lucigenin (Luc). The volume of each CL reactor was about 10 µL. A solution containing EP and Luc and a solution containing NaOH and periodate were injected successively into each inlet of the CL reactor in the range 20–100 µL/min with a pressure‐driven flow system. The intensity of light emission was dependent on the geometry of the flow reactors. These results could be explained in terms of the differences in the diffusion length of the reactants in the flow reactors. The maximum light emission were linearly correlated, with the concentrations of EP over the range from the detection limit of 5.0 × 10−8 mol/L up to 5.0 × 10−6 mol/L on the use of the CL reactor with the most promising geometry. Copyright © 2001 John Wiley & Sons, Ltd.