Ion detection using a pillar chip
Methods and assemblies for ion detection in samples using a chip with elevated sample zones, also known as a “pillar chip.” Methods include analyzing such a sample by desorbing a sample from a chip, producing a described ion sample and detecting the same. The chip comprises a base having a surface and one or more structures protruding above the surface of the base. Each structure comprises a pillar and a sample zone, the latter containing a support material and the sample to be analyzed. Assemblies include a chip such as that described above and a conductive element that comprises an aperture of sufficient proportion to allow passage of a molecular ion and that is adapted to be at a different electrical potential than the base of the chip.
1. A method comprising:
(a) desorbing a sample from a chip to produce a desorbed ion sample, wherein the chip comprises:
i. a base having a surface, and
ii. one or more structures protruding above the surface of the base, each structure comprising a pillar and a sample zone, wherein the sample zone comprises a support material and the sample;
(b) detecting the desorbed ion sample with an ion detector,
wherein the desorbed ion sample from step (a) is detected by the ion detector in step (b) without passing through any fluid transporting device.
2. The method of claim 1 further comprising allowing the desorbed ion sample to pass through an aperture in a conductive element, wherein the conductive element comprises a different electrical potential than the base.
3. The method of claim 2 , wherein the position of the chip is translatable, wherein the method further comprises aligning the aperture with one of the structures whereby the desorbed ion sample passes through the aperture after (a) but before (b).
4. The method of claim 2 , further comprising directing radiation at the sample zone before (a) through a window in the conductive element.
5. The method of claim 1 , wherein said support material receives radiation.
6. The method of claim 1 , wherein each pillar and the base comprise the support material that receives radiation.
7. The method of claim 1 , wherein said support material is porous.
8. The method of claim 1 , wherein said support material is conducting or semiconducting.
9. The method of claim 1 , wherein said support material is capable of transferring energy to the sample after receiving radiation.
10. The method of claim 1 , wherein the support material is coated with a surface coating comprising a binding reagent, wherein the binding reagent interacts with the sample.
11. The method of claim 10 , wherein the interaction between the binding reagent and the sample is a specific binding event.
12. The method of claim 1 , wherein the pillar and sample zone are identical in chemical composition.
13. The method of claim 1 , further comprising directing radiation at the sample zone before (a).
14. The method of claim 1 , wherein the ion detector forms part of a mass spectrometer.