Using squaraine dyes as near infrared fluorescent sensors for protein detection

Patent metadata

Field	Value
Publication number	US-9920020-B2
Application number	US-201213459837-A
Country	US
Kind code	B2
Filing date	Apr 30, 2012
Priority date	Apr 29, 2011
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

Squaraine dyes are used to detect the presence of protein in a test sample, which is a substance that may contain protein. A squarine dye is placed in water, and in some instances joined with an aggregation agent, to create an aqueous dye solution. That dye solution is joined with a test sample. When the dye solution is joined with the test sample and the resultant test solution is excited by the application of photons, a resulting fluorescence or absence thereof reveals if protein was present in the test sample.

First claim

What is claimed is:

1. A method for the detection of protein comprising the steps of:
preparing an aqueous dye solution comprising aggregated squaraine dyes by combining squaraine dyes and an aggregation agent selected from an anionic surfactant and graphene oxide, where the aggregation agent serves to promote the formation of aggregates of the squaraine dyes in the aqueous dye solution,
joining the aqueous dye solution with a test sample including a protein to prepare a test solution, and
exciting the test solution at a wavelength of about 635 nm to about 650 nm.

2. The method of claim 1 , where the aggregation agent is an anionic surfactant.

3. The method of claim 2 , where the anionic surfactant is selected from the group consisting of sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), tetraethylammonium dodecylbenzenesulfonate (DBS), and dioctyl sodium sulfosuccinate (DSS).

4. The method of claim 1 , where the aggregation agent is graphene oxide.

5. The method of claim 1 , where the squaraine dyes include a squaraine dye defined by the formula:

wherein R 1 is a counterion and R 2 is selected from the group consisting of:

6. The method of claim 5 , where the counter ion is selected from the group consisting of trifluoromethanesulfonate (CF 3 SO 3 − ) and iodide (I − ).

7. The method of claim 1 , where the squaraine dyes include a squaraine dye defined by the formula:

wherein R 2 is selected from the group consisting of

8. A method for the detection of protein comprising the steps of:
preparing test solution that includes protein and aggregated squaraine dyes prepared by combining squaraine dyes and an aggregation agent selected from anionic surfactants and graphene oxide;
exciting the test solution, and
detecting a fluorescent response.

9. The method of claim 8 , where the step of exciting the test solution is performed using an excitation wavelength that is between 400 and 700 nanometers.

10. A method for the detection of protein comprising the steps of:
preparing an aqueous dye solution comprising aggregated squaraine dyes by combining squaraine dyes and an aggregation agent,
joining the aqueous dye solution with a test sample including a protein to prepare a test solution, and
exciting the test solution at a wavelength of about 635 nm to about 650 nm; where the squaraine dyes include a squaraine dye defined by the formula:

wherein R 1 is a counterion and R 2 is selected from the group consisting of:

or where the squaraine dyes include a squaraine dye defined by the formula:

wherein R 2 is selected from the group consisting of

11. The method of claim 10 , where the squaraine dyes include a squaraine dye defined by the formula:

wherein R 1 is a counterion and R 2 is selected from the group consisting of:

12. The method of claim 11 , where the counter ion is selected from the group consisting of trifluoromethanesulfonate (CF 3 SO 3 − ) and iodide (I − ).

13. The method of claim 10 , where the squaraine dyes include a squaraine dye defined by the formula:

wherein R 2 is selected from the group consisting of

14. The method of claim 10 , where the aggregation agent is an anionic surfactant.

15. The method of claim 10 , where the aggregation agent is graphene oxide.

Assignees

• Pang Yi
• Xu Yongqian
• Univ Akron

Inventors

• Pang Yi
• Xu Yongqian

Classifications

• G01N2021/6495

  Miscellaneous methods · CPC title

• C07D417/14

  containing three or more hetero rings · CPC title

• C07D277/64 Primary

  with only hydrocarbon or substituted hydrocarbon radicals attached in position 2 · CPC title

• C09B57/007

  Squaraine dyes · CPC title

• G01N33/6839

  involving dyes, e.g. Coomassie blue, bromcresol green · CPC title