Sensor unit for assay in utilizing attenuated total reflection

• US 20060159591A1
• Filed: 01/18/2006
• Published: 07/20/2006
• Est. Priority Date: 01/18/2005
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Ohtsuka, Hisashi
• Granted Patent: US 7,682,566 B2
• Time in Patent Office: Days
• US Class Current: 422/88
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/15 Preventing contamination of the components of the optical system or obstruction of the light path
• CPC Class Codes: G01N 21/553 and using surface plasmons fluorescence excitation G01N21/648; enhanced Raman G01N21/658

Abstract

A surface plasmon resonance assay apparatus is loaded with a sensor unit. A sensing surface of a thin film detects reaction of a sample. A dielectric prism is overlaid with the thin film to constitute an interface. A reflection angle upon occurrence of attenuated total reflection of the illuminating light is changeable according to reaction of the sample on the sensing surface. Protecting panels are disposed to face outer surfaces of the prism, for covering and protecting at least partially the outer surfaces. A first window in one of the protecting panels is positioned on a path of the illuminating light traveling for incidence on the interface, for passing the illuminating light. A second window in one remaining protecting panel is positioned on a path of the illuminating light traveling upon reflection by the interface, for passing the illuminating light.

Claims

1. A sensor unit, including a dielectric block provided with a thin film disposed on a surface thereof, said thin film having a sensing surface for detecting reaction of a sample, wherein illuminating light is applied to an interface in a form satisfying a total reflection condition, said interface being defined between said thin film and said dielectric block by connection of said surface of said dielectric block back to said sensing surface, and when said sample in said sample fluid contacts said sensing surface, an angle of incidence of said illuminating light upon occurrence of attenuation is changed according to reaction of said sample, said sensor unit comprising:

a protector, disposed to face an outer surface of said dielectric block, for covering and protecting at least partially said outer surface; and

windows, formed in said protector, positioned on a path of said illuminating light traveling for incidence on said interface, and on a path of said illuminating light traveling upon reflection by said interface, for passing said illuminating light.

2. A sensor unit as defined in claim 1, wherein said dielectric block is constituted by a prism having a polygonal shape as viewed in a section, said surface with said thin film is directed upwards, and said protector is positioned on two outer surfaces of said prism.

3. A sensor unit as defined in claim 1, further comprising:

a flow channel block, having a flow channel, secured to said dielectric block by orientation to set said flow channel at said sensing surface, said flow channel causing a flow of said sample fluid on said sensing surface; and

a sealing structure secured over said flow channel block, for retaining said flow channel block on said dielectric block, and for closing said flow channel in a tightly engaged manner.

4. A sensor unit as defined in claim 3, wherein said windows are constituted by openings.

5. A sensor unit as defined in claim 3, wherein said protector and said sealing structure are included in one piece.

6. A sensor unit as defined in claim 5, wherein said sealing structure includes:

a first panel secured to said flow channel block over a surface thereof oriented upwards; and

first and second lateral protecting panels, disposed on said first panel to extend downwards from respectively first and second edges thereof, for covering outer surfaces of said dielectric block, said protecting panels constituting said protector.

7. A sensor unit, including a dielectric block provided with a thin film disposed on a surface thereof, said thin film having a sensing surface for detecting reaction of a sample, wherein illuminating light is applied to an interface in a form satisfying a total reflection condition, said interface being defined between said thin film and said dielectric block by connection of said surface of said dielectric block back to said sensing surface, and when said sample in said sample fluid contacts said sensing surface, an angle of incidence of said illuminating light upon occurrence of attenuation is changed according to reaction of said sample, said sensor unit comprising:

a protection layer, overlaid on an outer surface of said dielectric block, for protecting a region defined by passing said illuminating light of incidence on said interface, and a region defined by passing said illuminating light of reflection by said interface.

8. A sensor unit as defined in claim 7, wherein said dielectric block is constituted by a prism having a polygonal shape as viewed in a section, said surface with said thin film is directed upwards, and said protection layer is positioned on two outer surfaces of said prism.

9. A sensor unit as defined in claim 8, wherein said protection layer is constituted by a peelable protection tape, and said protection tape is peeled away before assay of said reaction of said sample.

10. A sensor unit as defined in claim 8, wherein said protection layer is transparent and formed by applying a coating to said outer surface.

11. A sensor unit as defined in claim 10, wherein said protection layer is formed from a material containing at least one of fluoride and titanium oxide.