DIRECT MONITORING OF ENZYME-CATALYZED REACTIONS VIA LASER-BASED POLARIMETRY

A new method Is described in which a laser-based polarimetric detection system is used to monitor enzyme-catalyzed reactions. This method provides direct detection of the reaction progress based on the inherent chirality of either the substrate or product. The technique is tested on the glucose oxidase catalyzed conversion of β-D-glucose to D-gluconic acid. The ability of this system to negate the large background signals produced by optically active substrates is examined, and a mass limit-of-detection for glucose oxidase of 34 fmol is demonstrated. Results obtained with the polarimetric technique are compared to those from an accepted spectrophotometric method, and the technique is shown to be as accurate with an LOD 15 times lower. The theoretical relationship between the polarimetric response and various experimental parameters will be developed and verified. © 1990, American Chemical Society. All rights reserved.