Versatile substrate for SPR detection
A substrate for testing a carrier liquid for biomolecules using SPR or other techniques provides a metallic island surrounded by a hydrophobic layer, the islands being a location for the attachment of probe molecules. The hydrophobic layer may also be a dielectric material providing improved sensitivity in SPR imaging.
1. A method of chemical analysis comprising the steps of:
(a) preparing a transparent support substrate having a metallic film adhered to a dielectric layer in turn attached to the support substrate, the metallic film having exposed regions surrounded by a hydrophobic material;
(b) attaching at least one probe molecule to the exposed regions of the metallic film;
(c) reacting probe molecules attached to the metallic film with a target material in a carrier solution coming into contact with an exposed metallic film surface;
(d) detecting the reaction using variations in reflectivity caused by surface plasmon resonance; and
(e) detecting the reaction through sensing of labeling of the target material at different locations.
2. The method of claim 1 wherein the dielectric layer is selected to substantially increase a change in reflectivity caused by surface plasmon resonance for a given amount of reaction.
3. The method of claim 1 wherein the dielectric layer has an index of refraction of 1.3 to 1.7.
4. The method of claim 1 wherein the step of detecting uses a camera forming an image of the substrate over two dimensions.
5. The method of claim 1 wherein the labeling is selected from groups consisting of fluorescent and radioactive labeling.
6. The method of claim 1 , further comprising the step of adhering a hydrophobic material to the substrate to expose separated islands of metal.
7. The method of claim 1 wherein the step of detecting the reaction comprises comparing exposed regions of the metallic film to regions covered by the hydrophobic material.