Fiber-optic biosensor and biosensing methods

• US 20060286680A1
• Filed: 02/16/2006
• Published: 12/21/2006
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: Research Foundation Incorporated University of Louisville, University of Cincinnati
• Original Assignee: University of Cincinnati, University of Louisville Research Foundation
• Inventors: Ahn, Chong H., Kang, Kyung Aih
• Granted Patent: US 8,563,328 B2
• Time in Patent Office: Days
• US Class Current: 436/518
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings

Abstract

A method for biosensing that includes passing, via convective flow, a sample believed to contain one or more target biomarkers through a microfluidic channel and over the surface of an optical waveguide that has been prepared to bind the one or more target biomarkers, and sensing for an emission output from the optical waveguide at a wavelength that is characteristic of the binding of the target biomarker. A biosensor device that includes a module defining at least one microfluidic channel, an optical waveguide exposed along at least a portion of its length to fluid flow within the microfluidic channel, where a surface of the optical waveguide being prepared to bind a target biomarker, and an excitation source to couple an excitation wavelength of light into the optical waveguide. The device also includes a sensor for detecting emission light from the optical waveguide at an emission wavelength characteristic of binding of the target biomarker.

Claims

1. A biosensing method for simultaneously detecting and quantifying one or more target biomarkers associated with a particular disease for accurate and rapid disease diagnosis and prognosis, said method comprising:

providing at least one optical waveguide;

selecting 1°

Mabs corresponding to each of the one or more target biomarkers;

immobilizing the 1°

Mabs on the optical waveguide;

exposing to the 1°

Mabs a sample believed to contain the target biomarkers using convective flow;

providing fluorophore-tagged 2°

Mabs corresponding to the target biomarkers;

exciting the at least one optical waveguide; and

observing a fluorescence emission to determine the presence and quantity of the target biomarkers.

2. The method of claim 1 further comprising providing at least two quartz optical sensing fibers coupled to one another in series.

3. The method of claim 1 further comprising providing four optical sensing fibers coupled to one another in series.

4. The method of claim 3 further comprising providing four 1°

Mabs corresponding respectively to cTnI, MG, BNP and CRP.

5. The method of claim 3 further comprising providing four 1°

Mabs corresponding respectively to PC, PS, ATIII and PLG.

6. The method of claim 1 further comprising selecting the 1°

and 2°

Mabs such that the 1°

has lower affinity with respect to the target biomarker than does the 2°

Mab.

7. The method of claim 1 further comprising immobilizing the 1°

Mab via an avidin-biotin bridge on a surface of the optical sensing fibers.

8. The method of claim 1 further comprising providing fluorescence enhancers to enhance fluorescence emission of the fluorophore.

9. The method of claim 8 further comprising providing a nanometal particle at a predetermined distance from the fluorophore.

10. The method of claim 9 further comprising providing one of the group consisting of nanogold particles, nanosilver particles, a reagent containing nanogold particles and a reagent containing nanosilver particles.

11. The method of claim 9 further comprising surrounding the nanometal particle with a self-assembled monolayer to maintain the predetermined distance between the fluorophore and the nanometal particle.

12. The method of claim 1 further comprising regenerating the optical sensing fibers.

13. The method of claim 1 further comprising coupling a spectrometer to the optical sensing fibers to determine fluorescence emission.

14. The method of claim 1 further comprising selecting the fluorophore from the group consisting of as Cy5, AF647, ATTO 647, Bodipy 650/665 and DY-636.

15. A biosensor for use with the method of claim 1, said biosensor comprising:

a housing;

a reservoir plate coupled to said housing, said reservoir plate having at least one inlet and at least one outlet and a microfluidic network fluidly coupling said inlet and said outlet;

a plurality of valves and at least one pump disposed within said microfluidic network;

a disposable biochip configured to be coupled to, and in fluid communication with, said reservoir plate, said biochip having four sensing channels disposed therein, each of said channels being configured to receive one of the optical sensing fibers;

a power source;

a drive circuit; and

a data acquisition card.

16. An automatic, portable biosensor for simultaneously detecting and quantifying a plurality of target biomarkers for rapid disease diagnosis and prognosis, said biosensor comprising:

a biochip having a plurality of microchannels disposed therein;

at least one optical waveguide configured to be disposed within a respective one of said microchannels, and being further configured to have an optimized sensing end portion on which to conduct a fluorophore mediated sandwich immunoassay;

a plurality of reagent reservoirs; and

a microfluidic network disposed between said biochip and said reagent reservoirs to maintain fluid communication between said biochip and said reagent reservoirs, said microfluidic network including a plurality of microchannels, a plurality of reagent valves corresponding to each of said reagent reservoirs, a pump, and a three way valve.

17. The biosensor of claim 16 further comprising four quartz optical sensing fibers coupled in series.

18. The biosensor of claim 17 further comprising optimized sensing portions disposed at a first end of said four quartz optical sensing fibers.

19. The biosensor of claim 16 further comprising a bubble trap for removing bubbles from the microchannels.

20. The biosensor of claim 16 further comprising a serpentine binding enhancer disposed within each of said microchannels.

21. A biosensor device, said device comprising:

a module defining at least one microfluidic channel;

an optical waveguide exposed along at least a portion of its length to fluid flow within said microfluidic channel, a surface of said optical waveguide being prepared to bind a target biomarker;

an excitation source to couple an excitation wavelength of light into said optical waveguide; and

a sensor for detecting emission light from said optical waveguide at an emission wavelength characteristic of binding of the target biomarker.

22. The biosensor device of claim 21, said module further comprising four microfluidic channels.

23. The biosensor device of claim 22 further comprising four quartz optical sensing fibers, each of which is configured to be at least partially disposed within one of said four microfluidic channels and fluidly coupled to one another in series.

24. A method for biosensing, said method comprising the steps of:

passing, via convective flow, a sample believed to contain one or more target biomarkers through a microfluidic channel and over the surface of an optical waveguide that has been prepared to bind the one or more target biomarkers;

sensing for an emission output from the optical waveguide at a wavelength that is characteristic of the binding of the target biomarker.

25. The method of claim 24 further comprising passing the sample through four microfluidic channels, each of said microfluidic channels having an optical waveguide disposed at least partially therein, where each optical waveguide is prepared to bind one of the one or more target biomarkers.

26. The method of claim 24 further comprising passing the sample over one or more quartz optical fibers that have been prepared to bind the one or more target biomarkers.

27. The method of claim 24 further comprising providing a nanometal particle reagent and exposing the nanometal particle reagent to the optical waveguide via convective flow.