Fluidic Biosensors with Integrated Surface Bound Hydrogel Sensing Elements

Optical sensors are a common tool to measure the dissolved oxygen concentration in environmental, industrial and medical areas. Much effort has been put on developing and using novel optical dyes and materials used as the immobilization matrixes. A poly (ethylene glycol) (PEG)-rich hydrogel was used as a fluorophore matrix. For optical sensor applications, this hydrogel was chemically anchored on negative-tone photopolymer SU-8 surface through a free radical reaction in which 1-hydroxycyclohexyl phenyl ketone (HCPK) served as the surface bound photoinitiator. Dissolved oxygen concentrations were detected based on the fluorescent intensity at emission wavelength of a fluorophore, dichlorotris (1, 10-phenanthroline) ruthenium (II) hydrate 98%, toward dissolved oxygen molecules. The normal characteristics of optical dissolved sensor were measured and recorded. All the results indicate the potential use of patternable polymerized PEGDA membranes, which is chemically anchored to SU-8 surface, as an ideal candidate matrix based on polymeric channel structures