Methods of making substrates for mass spectrometry analysis and related devices
View Patent ↗Substrates, methods for making the substrates and methods for using the substrates for mass spectrometry analysis are provided. Methods include coating a conductive substrate having a hydrophilic surface (suitable for mass spectrometric analysis) with an uncharged hydrophobic surface, masking a subset of regions on the hydrophobic surface with an insulator, and applying an oxidizing force to the unmasked regions of the hydrophobic surface to render the unmasked regions hydrophilic.
1. A support suitable for mass spectrometric analysis comprising:
a conductive substrate; and
discrete hydrophobic and hydrophilic regions on the substrate surface,
wherein the hydrophilic regions have a contact angle less than or equal to 14 degrees.
2. The support of claim 1 , wherein the hydrophilic regions have a contact angle less than or equal to 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 degrees.
3. The support of claim 1 , wherein the contact angle differential between the hydrophobic and hydrophilic regions is greater than 55, 60, 65, 70, 75, 80, 85 or 90 degrees.
4. The support of claim 1 , wherein the hydrophobic surface is substantially non-retroreflective.
5. The support of claim 1 , wherein the hydrophilic regions have a surface energy of about 73 mJ/m 2 .
6. The support of claim 1 , wherein the hydrophilic regions occupy less surface area than the hydrophobic regions.
7. The support of claim 1 , wherein the hydrophilic regions are uniformly spaced on the substrate.
8. The support of claim 1 , wherein the hydrophilic regions are obtained by treatment with an oxidizing force.
9. The support of claim 8 , wherein the oxidizing force is selected from corona discharge, plasma treatment and laser treatment.
10. The support of claim 9 , wherein the oxidizing force is corona discharge.
11. The support of claim 1 , wherein the hydrophobic surface is devoid of inorganic oxide particles.
12. The support of claim 1 , wherein the conductive substrate comprises a surface material that has an available —OH or primary amine.
13. The support of claim 1 , wherein the hydrophobic region is dimethyldichlorosilane (DMDCS); and the substrate is selected from the group consisting of a metal, a plastic and a silicon or silicon dioxide, which forms the hydrophilic regions.
14. The support of claim 1 , wherein the percentage of the total spectra obtained, when the substrate is used for mass spectrometric analysis, that are at a mass deviation of ≦0.5 Da is a percentage of the total spectra obtained selected from ≧25%, ≧30%, ≧40%, ≧50%, ≧55%, ≧60%, ≧65%, ≧70%, ≧75% of the total spectra obtained.
15. The support of claim 1 , wherein the percentage of the total spectra obtained, when the substrate is used for mass spectrometric analysis, that are at a mass deviation of ≦1.0 Da is a percentage of the total spectra obtained selected from ≧40%, ≧50%, ≧55%, ≧60%, ≧65%, ≧70%, ≧75%, ≧80%, ≧85%, ≧90%, ≧91%, ≧92%, ≧93%, ≧94%, ≧95%, ≧96%, ≧97%, ≧98%, ≧99%, ≧99.9% of the total spectra obtained.
16. The support of claim 1 , which further comprises a sample component.
17. The support of claim 16 , wherein the sample component is a nucleic acid and/or a protein.
18. The support of claim 1 , which further comprises a matrix material.
19. A method for mass spectrometric analysis comprising:
applying matrix material and sample to the hydrophilic regions on the support of claim 1 ;
introducing the substrate into a mass spectrometer for analysis of the samples; and
analyzing the samples by mass spectrometry.
20. A method of making a support suitable for mass spectrometric analysis, comprising:
masking a subset of regions on the surface of a support comprising a hydrophobic surface; and
applying an oxidizing force to the unmasked regions of the hydrophobic surface to render the unmasked regions hydrophilic under conditions that result in the hydrophilic regions having a contact angle less than or equal to 14 degrees against water.