Abstract: The present invention provides methods for the immobilization of molecules to a surface using a hydrogel. In particular, the invention relates to the formation and use of a hydrogel in a microscale environment, such as that used for the screening of molecules with microfabricated mechanical resonant sensors. In a preferred embodiment, the molecule is coupled to polyethylene glycol, or a block co-polymer and/or derivative thereof, and immobilized to a planar oxide surface that has been silanized. The immobilized molecule can then be used in a microscale screening or binding assay in an optimal hydrogel environment.