High efficiency optical detection of biomolecules in micro-capillaries

Patent metadata

Field	Value
Publication number	US-11549881-B2
Application number	US-201816486797-A
Country	US
Kind code	B2
Filing date	Feb 19, 2018
Priority date	Feb 20, 2017
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

Disclosed herein are systems, methods, and techniques for optical detection of analytes (e.g., biomarkers or other objects) using a liquid-core waveguide in which the analytes are suspended in a high-index liquid inside a liquid channel of the waveguide. The term “high-index” may indicate a refractive core index of the carrier liquid that is higher than or equal to that of one or more surrounding cladding layer(s) (e.g., ethylene glycol liquid inside a glass channel). In some embodiments, a method includes illuminating, by a light-source, one or more particles in a liquid-core waveguide, wherein the liquid-core waveguide comprises a first cladding layer having a first index of a refraction, and a hollow core comprising a liquid inside the hollow core, wherein the liquid has a second index of refraction higher than the first index of refraction; and detecting, by a detector, light emitted from the one or more particles.

First claim

What is claimed is:

1. A method for particle detection, the method comprising:
illuminating, by a light source, one or more particles in a liquid-core waveguide configured to support a fundamental transverse electromagnetic mode of light from the light source, wherein the liquid-core waveguide comprises:
a first cladding layer having a first index of a refraction; and
a hollow core extending through the waveguide and comprising a liquid inside the hollow core, wherein the liquid has a second index of refraction higher than the first index of refraction; and
a second cladding layer between the first cladding layer and the hollow core, wherein the second cladding layer has a third index of refraction, wherein the second and third indices of refraction are such that an intensity of a fundamental electromagnetic mode at an interface between the second cladding layer and the hollow core is greater than or equal to 20% of a maximum intensity of the fundamental transverse electromagnetic mode; and

detecting, by a detector, light emitted from the one or more particles.

2. The method of claim 1 , further comprising introducing the one or more particles into the liquid prior to illuminating the one or more particles.

3. The method of claim 1 , further comprising introducing the liquid into the hollow core prior to illuminating the one or more particles.

4. The method of claim 1 , wherein the first index of refraction is less than or equal to 1.4.

5. The method of claim 1 , wherein the second index of refraction is greater than or equal to 1.4.

6. The method of claim 1 , wherein the waveguide is configured to transmit light from the light source via total internal reflection.

7. The method of claim 1 , wherein the hollow core is less than or equal to 20 μm in width.

8. The method of claim 1 , wherein the first cladding layer is less than or equal to 10 μm in thickness.

9. The method of claim 1 , wherein the first cladding layer comprises one or more of: silicon dioxide, tantalum pentoxide, silicon nitride, PDMS, and one or more plastics.

10. The method of claim 1 , wherein the liquid-core waveguide is disposed on a substrate less than or equal to 2 cm in width and less than or equal to 2 cm in length.

11. The method of claim 10 , wherein the light source is disposed on the substrate.

12. The method of claim 10 , wherein the detector is disposed on the substrate.

13. The method of claim 1 , wherein the liquid comprises one or more of: zinc iodide, ethylene glycol, and sodium iodide.

14. The method of claim 1 , wherein the one or more particles comprise one or more of: molecules, particles, biomarkers, nucleic acids, proteins, and DNA.

15. The method of claim 1 ,
wherein the third index of refraction is the same as the second index of refraction or is within +/−10%, of the second index of refraction.

16. The method of claim 1 , wherein the second cladding layer is less than or equal to 1 μm.

17. The method of claim 1 , wherein the second cladding layer comprises one or more of: silicon dioxide, tantalum pentoxide, silicon nitride, PDMS, and plastic.

18. The method of claim 1 , further comprising identifying one or more of the detected particles on the basis of a detected characteristic.

19. A particle detection system comprising:
a light source configured to excite one or more particles;
a liquid-core waveguide configured to support a fundamental transverse electromagnetic mode of light from the light source, comprising:
a first cladding layer having a first index of refraction;
a hollow core extending through the waveguide and comprising a liquid inside the hollow core, wherein:
the liquid has a second index of refraction higher than the first index of refraction; and
the liquid comprises the one or more particles;

a second cladding layer between the first cladding layer and the hollow core, wherein the second cladding layer has a third index of refraction, wherein the second and third indices of refraction are such that an intensity of a fundamental electromagnetic mode at an interface between the second cladding layer and the hollow core is greater than or equal to 20% of a maximum intensity of the fundamental transverse electromagnetic mode; and
a detector configured to detect light emitted from the one or more particles.

20. The particle detection system of claim 19 , wherein the third index of refraction is the same as the second index of refraction or is within +/−10% of the second index of refraction.

21. The particle detection system of claim 19 , wherein the liquid-core waveguide is disposed on a substrate less than or equal to 2 cm in width and less than or equal to 2 cm in length.

22. The particle detection system of claim 21 , wherein the light source is disposed on the substrate.

23. The particle detection system of claim 21 , wherein the detector is disposed on the substrate.

Assignees

• Univ California

Inventors

• Schmidt Holger

Classifications

• G01N2015/1486

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• G01N2021/6482

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• G01N2021/6467

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• G01N21/645 Primary

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• G01N2021/0346

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