Optical assaying method and system having movable sensor with multiple sensing regions

• US 20010031503A1
• Filed: 05/30/2001
• Published: 10/18/2001
• Est. Priority Date: 11/19/1997
• Status: Active Grant

• Current Assignee: Richard R. Ollmann, William A. Challener
• Original Assignee: Richard R. Ollmann, William A. Challener
• Inventors: Challener, William A., Ollmann, Richard R.
• Granted Patent: US 6,653,152 B2
• Time in Patent Office: Days
• US Class Current: 436/518
• CPC Class Codes: G01N 21/553 and using surface plasmons fluorescence excitation G01N21/648; enhanced Raman G01N21/658
• CPC Class Codes: G01N 21/554 detecting the surface plasmon resonance of nanostructured metals, e.g. localised surface plasmon resonance
• CPC Class Codes: G01N 21/7743 the reagent-coated grating coupling light in or out of the waveguide
• CPC Class Codes: Y10S 435/808 Optical sensing apparatus
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/809 Multifield plates or multicontainer arrays

Abstract

An optical assaying method and system having a movable sensor is described. In one aspect, the present invention is a sensing system having a rotating sensor disk coated with indicator dyes sensitized to a variety of substances. In this configuration the sensing system further includes a detector for sensing spectral changes in light received from one or more of the indicator dyes. In another aspect, the present invention is a sensing system having a surface plasmon resonance sensor disk having grooves extending radially from a center of the disk. In yet another aspect, the present invention is a sensing system including a diffraction anomaly sensor disk having a dielectric layer that varies in thickness. The present invention allows for construction of an inexpensive sensing system that is capable of easily detecting a variety of substances either in a sample or a surrounding environment. Furthermore, the present invention provides a sensing system capable of sensing multiple substances without requiring multiple sensors.

Claims

1. A radial grating sensor disk, comprising:

a substrate having a plurality of grooves in a surface, wherein the grooves extend radially from a center of the surface;

a metal layer formed outwardly from the surface of the substrate, the metal layer substantially conforming to the grooved surface of the substrate; and

a sensitizing layer formed outwardly from the metal layer wherein the sensitizing layer is selected for interacting with at least one substance in a sample.

2. The disk of

claim 1

, wherein the grooves of the substrate have a constant period around a circumference of the sensor disk.

3. The disk of

claim 1

, wherein a period of the grooves of the substrate varies around a circumference of the sensor disk.

4. A method for assaying a substance in a sample comprising the steps of:

providing a sensor disk having a metal diffraction grating having a plurality of grooves extending radially from a center of the sensor disk to an outer edge of the sensor disk;

interacting the sensor with the sample;

rotating the sensor disk; and

determining a measure of the substance in the sample as a function of a shift in a position along a radius of the sensor disk at which light received from the sensor disk exhibits an anomaly.

5. The method of

claim 4

, wherein the grooves of the substrate have a constant period around a circumference of the sensor disk.

6. The method of

claim 4

, wherein the grooves of the substrate have a period which varies around a circumference of the sensor disk.