Microfabricated protein-containing poly(ethylene glycol) hydro239 arrays for biosensing

We describe the use of poly(ethylene glycol) (PEG) hydrogel microstructures containing immobilized enzymes such as acetylcholineste-rase (AChE) and urease for the detection of analytes. Changes in the microenvironment pH due to enzyme-catalyzed reaction with the analyte of interest were used to fluorescently detect low concentrations of the analyte. The hydrogel microstructures were prepared photo-lithographically on silicon surfaces. The use of a microarraying robot to create microstructured hydrogel array sensors is also described. A dual analyte sensor using this scheme is presented to demonstrate the ease of creation of such multianalyte sensors. Such micron-sized arrays can therefore be easily used as biosensors to detect small molecular weight analytes to extremely low concentrations in air or water. © 2003 Elsevier B.V. All rights reserved