Hydrogel polymer blends including precursors and crosslinked forms of the compositions. The blends provide an improved approach to achieve high quality, uniform coatings with better commercial viability than other approaches including copolymerization. Applications include mass spectral analysis of biomolecular analytes such as proteins. Dextran and acrylamide systems are preferred. Benzophenone groups can be used as photocrosslinking groups. Photoinitiators are not needed. Functionalities which can selectively bind to biomolecular analytes are included.