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

We describe the use of poly(ethylene glycol) (PEG) hydrogel microstructures containing immobilized enzymes such as acetylcholinesterase (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 photolithographically 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. (C) 2003 Elsevier B.V. All rights reserved.