Surface plasmon resonance

• US 20020182743A1
• Filed: 06/03/2002
• Published: 12/05/2002
• Est. Priority Date: 12/07/1999
• Status: Active Grant

• Current Assignee: Secretary of State For Defence
• Original Assignee: Secretary of State For Defence
• Inventors: Squirrell, David James, Perkins, Elaine Ann
• Granted Patent: US 6,753,188 B2
• Time in Patent Office: Days
• US Class Current: 436/164
• CPC Class Codes: G01N 21/553 and using surface plasmons fluorescence excitation G01N21/648; enhanced Raman G01N21/658

Abstract

The surface plasmon resonance apparatus (1) for detecting a soluble and/or particulate analyte comprises a prism sensor (2) providing a metallized sensor surface (3) capable of binding the analyte, and a laser (10) providing a beam (4) for direction at the sensor surface (3) A detector (5) is provided which is capable of detecting light (6), which is internally reflected from the sensor surface (3). Displacement means (7) comprising a vibrator (8) and mirror (9), is operable whereby the excitation beam (4) is displaced over an angular range (A) relative to the sensor surface (3). An analyte sample (15) is disposed on the metallic sensor (3). The detector (5) is used to interpret the light signals (6) internally reflected from the sensor surface (3) so that the sample (15) is analyzed. A video camera system (16), which includes a mirror (17), microscope objective (18) and CCD (charge-coupled device) array (19), is used to detect the scattered light emitted from the upper face of the sensor surface (3).

Claims

1. Surface plasmon resonance apparatus for detecting a soluble and/or a particulate analyte (15), comprising a sensor (2) having a metallised sensor surface (3) providing means for binding the analyte (15) thereto, a light source (10) providing an excitation beam (4) for directing at the sensor surface (3) and a first detector (19) for detecting light scattered by the sensor surface (3) characterised in that it further comprises a second detector (5) for detecting light reflected from the sensor surface (6) ad means for enhancing the light scattered by the sensor surface (7) by modifying the excitation beam (4).

2. Apparatus according to claim 1, characterised in that the means for enhancing the light scattered from the sensor surface (7) comprise feedback control means (63, 281, 391, 590).

3. Apparatus according to claim 1, characterised in that the means for enhancing the light scattered from the sensor surface (7) comprise feedback control means (281, 590) from the first detector (19).

4. Apparatus according to claim 3, characterised in that the feedback control means (281, 590) comprise automatic adjustment means (280) responsive to signals from the first detector (19).

5. Apparatus according to claim 4, characterised in that the automatic adjustment means (280) comprise means for adjusting the wavelength of the excitation beam (390).

6. Apparatus according to claim 4, characterised in that the automatic adjustment means (280) comprise means for displacing the excitation beam (110, 510) over a range of angles with respect to the sensor surface (3).

7. Apparatus according to any of claims 4 to 6, characterised in that the automatic adjustment means (280) are computer controlled.

8. Apparatus according to any preceding claim, characterised in that the first detector (19) comprises a charge-couple device array.

9. Apparatus according to any preceding claim, characterised in that the excitation beam (4) comprises a linear beam, a fan-shaped beam or a wedge-shaped beam.

10. A method of detecting a soluble and/or a particulate analyte based on surface plasmon resonance, comprising the steps of i) directing an excitation beam (4) at a sensor (2) comprising a metallised sensor surface (3) and means for binding the analyte (15) thereto and ii) detecting light scattered by the sensor surface with a first detector (19) characterised in that, it further comprises the steps of iii) detecting light (6) reflected from the sensor surface (3) at a second detector (5) and iv) enhancing the light scattered by the sensor surface by modifying the excitation beam (4).

11. A method according to claim 10, characterised in that the step of enhancing the light scattered from the sensor surface comprises providing feedback control means (63, 281, 391, 590).

12. A method according to claim 11, characterised in that the feedback control means (590) comprise automatic adjustment means (280) responsive to the first detector (19).