Photocrosslinked hydrogel blend surface coatings

Abstract

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.

1 - 94 . (canceled)  
   
   
       95 . A method for detecting a biomolecular analyte comprising: 
 a) providing a mass spectrometry probe comprising a surface that is coated at at least one addressable location with a crosslinked hydrogel polymer blend composition, wherein the composition comprises: 
 i. a plurality of first polysaccharide polymer molecules, and  
 ii. a plurality of second polysaccharide polymer molecules, wherein the second polysaccharide polymer molecules are different from the first polysaccharide polymer molecules and comprise a selective binding functionality, and  
 iii. wherein the first polysaccharide polymer molecules are photocrosslinked with each other and further photocrosslinked with the second polysaccharide polymer molecules through reacted benzophenone groups, wherein photocrosslinking results from photo-reacting benzophenone groups attached to the first polysaccharide polymer molecules;  
   b) contacting the composition with a sample that contains a biomolecular analyte, whereby the analyte binds to the selective binding moiety;    c) inserting the probe into a laser desorption/ionication mass spectrometer; and    d) detecting the bound biomolecular analyte by laser desorption/ionization mass spectrometry.    
   
   
       96 . The method according to  claim 95 , wherein the first and second polysaccharide polymer molecules comprise dextran.  
   
   
       97 . The method according to  claim 95 , wherein the selective binding functionality is selected from the group consisting of an anion exchange moiety, a cation exchange moiety, a metal ion complexing moiety, a metal complex, a polar moiety, a hydrophobic moiety, a mixed-mode moiety and combinations of these.  
   
   
       98 . The method according to  claim 95 , wherein the selective binding functionality is a biospecific binding functionality.  
   
   
       99 . The method according to  claim 98 , wherein the biospecific binding functionality is selected from the group consisting of antibodies, antigens, lectins, receptor proteins and nucleic acids.  
   
   
       100 . The method according to  claim 95 , wherein the selective binding functionality comprises a group for covalently binding a molecule.  
   
   
       101 . The method according to  claim 100 , wherein the selective binding functionality is an epoxide or a carbodiimidizole.  
   
   
       102 . The method according to  claim 95 , wherein the selective binding functionality is bound to an analyte selected from the group consisting of polypeptides, nucleic acids, carbohydrates and lipids.  
   
   
       103 . The method according to  claim 95 , wherein the hydrogel polymer blend composition is covalently bound to the surface.  
   
   
       104 . The method according to  claim 95 , wherein the hydrogel polymer blend composition is physically attached to the surface.  
   
   
       105 . The method according to  claim 95 , wherein the hydrogel polymer blend composition is a film having a film thickness of about 5 nm to about 50 microns.  
   
   
       106 . The method according to  claim 95 , wherein the hydrogel polymer blend composition is a film having a film thickness of about 1 micron to about 10 microns.  
   
   
       107 . The method according to  claim 95 , wherein the substrate comprises plastic.  
   
   
       108 . The method according to  claim 95 , wherein the substrate comprises a primer layer that comprises a silane, a hydrocarbon silane, a fluorinated silane, a mixed fluorinated/hydrocarbon silane, a polymer, an alkoxysilane, a chlorosilane, an alkanethiol or a disulfide.  
   
   
       109 . The method according to  claim 95 , wherein the substrate comprises plastic, glass, silicon, metal, or metal oxide.  
   
   
       110 . The method according to  claim 95 , wherein the hydrogel is a uniform layer on the surface.  
   
   
       111 . The method according to  claim 95 , wherein the hydrogel is in the form of discrete spots on the surface.  
   
   
       112 . The method according to  claim 95 , wherein the hydrogel polymer blend composition further comprises an energy absorbing moiety.  
   
   
       113 . The method according to any of claims  95 - 111 , wherein a matrix for laser desorption/ionization mass spectrometry is applied to the crosslinked hydrogel polymer blend composition.  
   
   
       114 . The method according to  claim 113 , wherein the first polysaccharide molecules are further photocrosslinked with the surface of the substrate through reacted benzophenone groups.  
   
   
       115 . The method according to claims  95 - 112 , wherein the first polysaccharide molecules are further photocrosslinked with the surface of the substrate through reacted benzophenone groups.