Processing microtitre plates for covalent immobilization chemistries

1. A method comprising:

treating an organic polymer with an electron beam-generated plasma;

exposing the treated polymer to air or an oxygen- and hydrogen-containing gas;

wherein the treating and exposing generates hydroxyl groups on the surface of the polymer;

reacting the surface with an organosilane compound having a chloro, fluoro, or alkoxy group and a functional or reactive group that is less reactive with the surface than the chloro, fluoro, or alkoxy group; and

covalently immobilizing a biomolecule to the functional or reactive group or a reaction product thereof.

2. The method of claim 1 , wherein the plasma is generated in argon, oxygen, carbon dioxide, dry air, humid air, a gas with water vapor, or a mixture thereof.

3. The method of claim 1 ;

wherein the plasma is generated in argon; and

wherein the plasma treatment operating conditions are within +/−10% of each of the following conditions: gas pressure of 90 mTorr, treatment time of 20 minutes, electron beam energy of 2 keV, electron beam current density of 4 mA/cm 2 , electron beam pulse width of 2 ms, electron beam pulse frequency of 50 Hz.

4. The method of claim 1 , wherein the organic polymer is polystyrene.

5. The method of claim 1 , wherein the organic polymer is a microtitre plate comprising a plurality of wells.

6. The method of claim 5 , wherein at least two different organosilane compounds are reacted with the surfaces of different wells.

7. The method of claim 5 , wherein the organosilane compounds in at least two different wells are each reacted with a different crosslinker before immobilizing the biomolecules.

8. The method of claim 1 ;

wherein the organosilane compound is R—SiX 3 ;

wherein R contains the functional or reactive group; and

wherein each X is an independently selected chemical group with the proviso that at least one X is chloro, fluoro, bromo, halo, or alkoxy group.

9. The method of claim 8 ;

wherein R— is R′—(CH 2 ) n —;

wherein n is a positive integer; and

wherein R′ contains the functional or reactive group.

10. The method of claim 1 , wherein the functional or reactive group is amine, thiol, aldehyde, carboxyl, nitrobenzyl-protected carboxyl, glycidoxy, thiocyano, isocyano, succinimidyloxy, succinimidyl ester, aryl azide, aryl azido, hydrazine, hydrazide, alkyl halide, benzyl halide, α-halo acetyl, or maleimide.

11. The method of claim 1 , wherein the organosilane compound is 3-mercaptopropyl trimethoxysilane, 3-mercaptopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, or 3-aminopropyl triethoxysilane.

12. The method of claim 1 , wherein the organosilane compound is in the form of a monolayer.

13. The method of claim 1 , wherein the functional or reactive group is reacted with a crosslinker or activated by light, pH, or hydration before incubating with the biomolecule.

14. The method of claim 1 , wherein the biomolecule is a peptide, an antimicrobial peptide, a carbohydrate, a lipid, an antibody, or a protein.

15. The method of claim 1 , wherein the electron temperature of the plasma is from about 0.3 to about 1 eV.

16. The method of claim 3 , wherein the electron temperature of the plasma is from about 0.3 to about 1 eV.