IMAGING OF CHEMILUMINESCENT REACTIONS IN MESOSCALE SILICON-GLASS MICROSTRUCTURES

Chemiluminescent reactions in mesoscale analytical structures (chips) containing micrometre-sized interconnecting channels and chambers (pL- nL total volume) were imaged. The chips were fabricated by bonding Pyr ex glass to etched pieces of silicon using a high-temperature diffusiv e bonding technique. In initial experiments light emission from an enh anced chemiluminescent horseradish peroxidase reaction and from a pero xyoxalate reaction contained in straight channels (300 mu m wide x 20 mu deep; volume 70.2 nL) and open chambers (812 mu m wide, 400 mu m de ep, 5.2 mm long) linked by channels (100 mu m wide, 20 mu m deep) to a n exit and entry port were studied using a specially modified micropla te holder and an Amerlite microplate luminometer. Light emission from more complex structures (two chambers interconnected by a branching ch annel 100 mu m wide, 20 mu m deep) filled with a solution containing a lkaline phosphatase, Emerald, and CSPDTM was imaged using a Photometri cs Star 1 CCD camera. Detailed investigation of the detection and spat ial resolution of the signal was performed on a Berthold Luminograph L B 980 using both the enhanced chemiluminescent horseradish peroxidase reaction and a peroxyoxalate reaction. We successfully resolved light emission from silicon structures with dimensions 100 mu m wide and 20 mu m deep. These simple silicon structures served as models for more c omplex designs that will be used for simultaneous multi-analyte assays in which an imaging system resolves and quantitates light emission fr om different locations on a silicon-glass analytical device.