Surface plasmon resonance sensor
An SPR sensor comprising a thin conducting layer comprising at least one conductive element formed on a surface of a transparent substrate, a light source that illuminates an interface between the conducting layer and the substrate, a photosensitive surface that generates signals from light reflected from the interface, a flow cell formed with at least one flow channel having a lumen defined by a wall formed from an elastic material and from a region of the conducting layer, and at least one hollow fluid-providing flow control apparatus having a lumen and an orifice communicating with its lumen. Fluid flow is enabled between the flow channel and the lumen of the flow control apparatus by forcing an end of the flow control apparatus through the elastic material so that the orifice communicates with the flow channel lumen.
1. A surface plasmon resonance (SPR) system comprising:
a) a thin conducting layer suitable for SPR formed on a transparent substrate, the conducting layer comprising a number of conducting strips;
b) a plurality of flow channels crossing the conducting strips at crossover regions;
c) an illumination system configured to illuminate an interface of the conducting layer and the substrate at the crossover regions, and at other regions of the conducting strips that are not crossover regions, at a plurality of different angles of incidence or different wavelengths; and
d) a photosensitive surface that generates SPR signals in response to light reflected from the illuminated crossover regions that can be used to determine an SPR parameter, and generates reference SPR signals in response to light reflected from the other regions, that can be used to normalize or correct the SPR signals from the crossover regions.
2. An SPR system according to claim 1 , wherein each of a plurality of the flow channels crosses each of a plurality of the conducting strips.
3. An SPR system according to claim 1 , which does not have valves for controlling a flow of liquid in the flow channels.
4. A system according to claim 1 , wherein the illumination system is configured to illuminate the interface, both at the crossover regions and at the other regions, at a plurality of angles of incidence at a same wavelength, the angle of incidence being selectable without using moving parts.
5. A system according to claim 4 , wherein the illumination system comprises an array of light sources at least some of which illuminate the interface at different angles of incidence at the same wavelength, the angle of incidence being selectable by suitably turning on and off the different light sources in the array.
6. A system according to claim 1 , wherein the illumination system is configured to illuminate the interface, both at the crossover regions and at the other regions, at a plurality of wavelengths at a same angle of incidence.
7. A system according to claim 6 , wherein the illumination system comprises an array of light sources at least some of which illuminate the interface at different wavelengths at a same angle of incidence, the wavelength being selectable by suitably turning on and off the different light sources in the array.
8. A method of measuring binding of a target material to an SPR surface, the method comprising:
a) passing a fluid sample with the same or a different target material through each of a plurality of flow channels that cross a number of conducting strips suitable for SPR, at crossover regions on which ligands are bound;
b) reflecting light from the crossover regions, and from other regions of the conducting strips that are not crossover regions;
c) generating SPR signals from the crossover regions and the other regions;
d) using the SPR signals from the crossover regions to determine an SPR parameter, to monitor binding of the target material to the ligands; and
e) using the SPR signals from the other regions to normalize or correct the SPR parameters of the crossover regions.
9. A method according to claim 8 , wherein each of a plurality of the flow channels crosses each of a plurality of the conducting strips.