Localized surface plasmon resonance sensing system, appartatus, method thereof

• US 8,305,583 B2
• Filed: 12/24/2009
• Issued: 11/06/2012
• Est. Priority Date: 11/11/2005
• Status: Active Grant

• Current Assignee: Instant NanoBiosensors Co., Ltd.
• Original Assignee: National Chung Cheng University
• Inventors: Chau, Lai-Kwan, Hsieh, Wen-Hsin, Hsu, Wei-Ting, Chen, Po-Liang
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): Lapage, Michael P
• Application Number:
  US12/647,251
• Publication Number:
  US 20100128275A1
• Time in Patent Office: 1,048 Days
• Field of Search: 356/445
• US Class Current: 356/445
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01N 21/554 detecting the surface plasmon resonance of nanostructured metals, e.g. localised surface plasmon resonance
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G02B 6/0229 characterised by nanostructures, i.e. structures of size less than 100 nm, e.g. quantum dots

Abstract

A sensing system comprises a light source, an optical fiber, a plurality of noble metal nano-particles, a micro-fluidic module and a photo detector. The optical fiber couples an incident light. The plurality of noble metal nano-particles are disposed on a surface of the optical fiber to form a noble metal nano-particle submonolayer, the noble metal nano-particles are substantially separated from each adjacent noble metal nano-particles such that the conductivity of the noble metal nano-particle submonolayer is smaller than that of a metal film. The micro-fluidic module accommodates the optical fiber and a sample, and the sample is driven to contact with the noble metal nano-particles. The photo detector detects an emergent light from the optical fiber. When the incident light interacts with the noble metal nano-particles, a signal derived from localized surface plasmon resonance in form of attenuated light or elastic scattered light is outputted through the photo detector.

Claims

1. A localized surface plasmon resonance sensing system, comprising:

a light source providing an incident light;

an optical fiber coupling the incident light, wherein there is not a polarizer or a microscope objective between the light source and the optical fiber;

a plurality of noble metal nano-particles being disposed on a surface of the optical fiber in an unclad region to form a noble metal nano-particle submonolayer, the noble metal nano-particles being substantially separated from each adjacent noble metal nano-particles such that the conductivity of the noble metal nano-particle submonolayer is smaller than that of a metal film, and the conductivity of the noble metal nano-particle submonolayer being smaller than 2×

10³ Ω

<sup>−

1</sup>m<sup>−

1</sup>.

a micro-fluidic module accommodating the optical fiber and a sample, and the sample being driven to contact with the noble metal nano-particles; and

at least one photo detector detecting a light intensity of an emergent light from the optical fiber without using any light collecting device or polarizer or microscope objective or spectral filter to aid light collection, wherein the emergent light is a transmitted light, a reflected light, or a leaked light from the unclad region and the emergent light is not a fluorescent light, and the photo detector directly detects the light intensity of the emergent light;

wherein when the incident light interacts with the noble metal nano-particles, a signal derived from localized surface plasmon resonance in the form of attenuated light or elastic scattered light is outputted through the photo detector.

2. The localized surface plasmon resonance sensing system as claimed in claim 1, wherein the light source provides the incident light with a single frequency or a narrow frequency band.

3. The localized surface plasmon resonance sensing system as claimed in claim 1, wherein the noble metal nano-particles are disposed at a stripped area, and the stripped area is formed by removing a cladding of the optical fiber partially.

4. The localized surface plasmon resonance sensing system as claimed in claim 1, wherein the noble metal nano-particles are gold nano-particles or silver nano-particles.

5. The localized surface plasmon resonance sensing system as claimed in claim 1, wherein the micro-fluidic module further comprises at least one inlet and at least one outlet, the inlet is disposed for inputting the sample, and the outlet is disposed for outputting the sample.

6. The localized surface plasmon resonance sensing system as claimed in claim 1, wherein the noble metal nano-particles are further modified with a recognition molecule for sensing an analyte in the sample.

7. A localized surface plasmon resonance sensing method comprising the steps of:

providing an incident light by a light source;

coupling the incident light by an optical fiber, wherein there is not a polarizer or a microscope objective between the light source and the optical fiber;

disposing a plurality of noble metal nano-particles on a surface of the optical fiber in an unclad region, and the noble metal nano-particles being substantially separated from each adjacent noble metal nano-particles such that the conductivity of the noble metal nano-particle submonolayer is smaller than that of a metal film, and the conductivity of the noble metal nano-particle submonolayer being smaller than 2×

10³ Ω

<sup>−

1</sup>m<sup>−

1</sup>;

accommodating the optical fiber and a sample in a micro-fluidic module;

driving the sample to contact with the noble metal nano-particles; and

detecting a light intensity of an emergent light from the optical fiber through at least one photo detector without using any light collecting device or polarizer or microscope objective or spectral filter to aid light collection, wherein the emergent light is a transmitted light, a reflected light, or a leaked light from the unclad region, and the emergent light is not a fluorescent light, and the photo detector directly detects the light intensity of the emergent light;

wherein when the incident light interacts with the noble metal nano-particles, a signal derived from localized surface plasmon resonance in the form of attenuated light or elastic scattered light is outputted through the photo detector.

8. The localized surface plasmon resonance sensing method as claimed in claim 7, wherein the light source provides the incident light with a single frequency or a narrow frequency band.

9. The localized surface plasmon resonance sensing method as claimed in claim 7, further comprising the step of:

disposing the noble metal nano-particles at a stripped area;

wherein the stripped area is formed by removing a cladding of the optical fiber partially.

10. The localized surface plasmon resonance sensing method as claimed in claim 7, wherein the noble metal nano-particles are gold nano-particles or silver nano-particles.

11. The localized surface plasmon resonance sensing method as claimed in claim 7, wherein the micro-fluidic module further comprises at least one inlet and at least one outlet, the inlet is disposed for inputting the sample, and the outlet is disposed for outputting the sample.

12. The localized surface plasmon resonance sensing method as claimed in claim 7, wherein the noble metal nano-particles are further modified with a recognition molecule for sensing an analyte in the sample.

13. A localized surface plasmon resonance sensing apparatus, comprising:

an optical fiber coupling an incident light, wherein the incident light does not pass any polarizer or microscope objective;

a plurality of noble metal nano-particles being disposed on a surface of the optical fiber in an unclad region, the noble metal nano-particles being substantially separated from each adjacent noble metal nano-particles such that the conductivity of the noble metal nano-particle submonolayer is smaller than that of a metal film, and the conductivity of the noble metal nano-particle submonolayer being smaller than 2×

10³ Ω

<sup>−

1</sup>m<sup>−

1</sup>; and

a micro-fluidic module accommodating the optical fiber and a sample, and the sample being driven to contact with the noble metal nano-particles;

wherein when the incident light interacts with the noble metal nano-particles, a signal derived from localized surface plasmon resonance in the form of attenuated light or elastic scattered light is outputted through a photo detector, and the photo detector detects a light intensity of an emergent light from the optical fiber without using any light collecting device or polarizer or microscope objective or spectral filter to aid light collection, wherein the emergent light is a transmitted light, a reflected light, or a leaked light from the unclad region, and the emergent light is not a fluorescent light, and the photo detector directly detects the light intensity of the emergent light.

14. The localized surface plasmon resonance sensing apparatus as claimed in claim 13, wherein the noble metal nano-particles are disposed at a stripped area, and the stripped area is formed by removing a cladding of the optical fiber partially.

15. The localized surface plasmon resonance sensing apparatus as claimed in claim 13, wherein the noble metal nano-particles are gold nano-particles or silver nano-particles.

16. The localized surface plasmon resonance sensing apparatus as claimed in claim 13, wherein the micro-fluidic module further comprises at least one inlet and at least one outlet, the inlet is disposed for inputting the sample, and the outlet is disposed for outputting the sample.

17. The localized surface plasmon resonance sensing apparatus as claimed in claim 13, wherein the noble metal nano-particles are further modified with a recognition molecule for sensing an analyte in the sample.