MALDI target plate utilizing micro-wells
View Patent ↗An arrangement for a MALDI sample plate for ion mass spectroscopy is disclosed. The sample is configured to shape the hypersonic explosion which creates the ions generated in a MALDI-type time-of-flight mass spectrometer. The MALDI sample plate includes a glass wafer formed from a plurality of clad glass fibers and has a first planar surface. The plate also has a plurality of micro-wells formed in the glass wafer. The micro-wells extend to a depth that is less than the thickness of the glass wafer and act to hold a spot sample in a manner that prevents spreading, maximizes the formation of ions, and shapes the resulting ion cloud to improve ion migration.
1. A method of making a sample support plate for use in a MALDI mass spectrometer comprising the steps of:
a. forming a multifiber billet comprising a plurality of clad glass fibers, each of the clad glass fibers comprising a soluble glass core and an insoluble glass cladding;
b. cutting a cross-sectional wafer from the multifiber billet;
c. exposing the wafer to a dissolving medium selected to dissolve the glass cores; and
d. controlling the time at which the wafer is exposed to the dissolving medium so that the glass cores are dissolved to a depth that is less than the thickness of the wafer.
2. The method of claim 1 comprising the step of rendering exposed surfaces of the wafer to be electrically conductive.
3. The method of claim 1 wherein the controlling step comprises the steps of
removing the wafer from the dissolving medium;
rinsing the wafer to remove residual dissolving medium; and then
drying the wafer.
4. The method of claim 1 wherein the dissolving medium used in step c. is an acidic solution.
5. The method of claim 1 comprising the step of applying a mask to one planar surface of the wafer so as to prevent dissolution of the glass cores on one side of the wafer.
6. The method of claim 1 wherein the step of cutting the cross-sectional wafer comprises the step of polishing the surfaces of the wafer before further processing.