Gold nanoparticle aggregation-induced quantitative photothermal biosensing using a thermometer

Patent metadata

Field	Value
Publication number	US-11860118-B2
Application number	US-202017112841-A
Country	US
Kind code	B2
Filing date	Dec 4, 2020
Priority date	Dec 5, 2019
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A biosensing system configured to detect a target DNA and methods of detecting a target DNS are presented. The biosensing system comprises a biosensor comprising a suspension of a hybridization buffer containing dispersed gold nanoparticles, sodium chloride, and single-stranded DNA probes configured to undergo DNA hybridization with the target DNA.

First claim

What is claimed is:

1. A method of detecting a target DNA, the method comprising:
adding a DNA sample to a biosensor comprising a suspension of a hybridization buffer containing dispersed gold nanoparticles, sodium chloride, and single-stranded DNA probes configured to undergo DNA hybridization with the target DNA;
sending, by a laser, a beam of near-infrared radiation into the biosensor, wherein the beam of near-infrared radiation is configured to induce a photothermal effect in any aggregated gold nanoparticles present in the biosensor; and
detecting a temperature of the biosensor after sending the beam of near-infrared radiation into the biosensor;
determining whether the target DNA is present in the DNA sample based on the temperature of the biosensor;
adding a first solution of the single-stranded DNA probes in the hybridization buffer to a suspension of the dispersed gold nanoparticles to form a protected gold nanoparticle suspension; and
adding a second solution of sodium chloride in the hybridization buffer to the protected gold nanoparticle suspension to form the biosensor.

2. The method of claim 1 further comprising:
determining, in response to a determination that the target DNA is present in the DNA sample, a concentration of the target DNA in the DNA sample.

3. The method of claim 2 , wherein determining the concentration of the target DNA comprises:
determining a temperature change using the temperature of the biosensor and an initial temperature of the biosensor; and
determining the concentration of the target DNA using the temperature change.

4. The method of claim 1 , wherein the first solution of the single-stranded DNA probes comprises a minimum concentration of single-stranded DNA probes configured to protect the dispersed gold nanoparticles from the sodium chloride, and wherein the second solution of the sodium chloride comprises a concentration of sodium chloride configured to produce a maximum temperature increase due to gold nanoparticle aggregation.

5. The method of claim 1 further comprising:
forming the DNA sample without DNA amplification.

6. A biosensing system configured to detect a target DNA, the biosensing system comprising:
a biosensor comprising a suspension of a hybridization buffer containing dispersed gold nanoparticles, sodium chloride, and single-stranded DNA probes configured to undergo DNA hybridization with the target DNA; and
a laser configured to direct a beam of near-infrared radiation into the biosensor, wherein the beam of near-infrared radiation is configured to induce a photothermal effect in any aggregated gold nanoparticles present in the biosensor,
wherein the dispersed gold nanoparticles have a diameter of at least 20 nanometers.

7. The biosensing system of claim 6 , wherein the biosensor is configured to operate such that the biosensor and a DNA sample to be introduced to the biosensor are label-free and DNA amplification-free.

8. The biosensing system of claim 6 further comprising:
a thermometer configured to detect temperature changes of the suspension.

9. The biosensing system of claim 6 , wherein the biosensor comprises a concentration of sodium chloride configured to produce a maximum temperature increase due to gold nanoparticle aggregation without triggering precipitation of aggregated gold nanoparticles.

10. The biosensing system of claim 9 , wherein the biosensor comprises a concentration of single-stranded DNA probes configured to interact with dispersed gold nanoparticles.

11. The biosensing system of claim 9 , wherein the biosensor comprises a concentration of single-stranded DNA probes configured to provide the biosensor with a temperature increase in response to a beam of near-infrared radiation equivalent to a temperature increase in response to a beam of near-infrared radiation of a suspension of dispersed gold nanoparticles.

12. The biosensing system of claim 6 , wherein the laser is a near-infrared (NIR) laser having a wavelength from about 750 nm to about 850 nm.

13. A biosensing system configured to detect a target DNA, the biosensing system comprising:
a biosensor comprising a suspension of a hybridization buffer containing dispersed gold nanoparticles, sodium chloride, and single-stranded DNA probes configured to undergo DNA hybridization with the target DNA;
a laser configured to direct a beam of near-infrared radiation into the biosensor, wherein the beam of near-infrared radiation is configured to induce a photothermal effect in any aggregated gold nanoparticles present in the biosensor; and
a thermometer configured to detect temperature changes of the suspension,
wherein the biosensing system has a limit of detection of about 0.28 nM.

14. A biosensing system configured to detect a target DNA, the biosensing system comprising:
a biosensor comprising a suspension of a hybridization buffer containing dispersed gold nanoparticles, sodium chloride, and single-stranded DNA probes configured to undergo DNA hybridization with the target DNA; and
a laser configured to direct a beam of near-infrared radiation into the biosensor, wherein the beam of near-infrared radiation is configured to induce a photothermal effect in any aggregated gold nanoparticles present in the biosensor,
wherein the biosensor comprises a concentration of sodium chloride configured to produce a maximum temperature increase due to gold nanoparticle aggregation without triggering precipitation of aggregated gold nanoparticles, and wherein the biosensor comprises a minimum concentration of single-stranded DNA probes configured to protect the dispersed gold nanoparticles from the sodium chloride.

15. A biosensing system configured to detect a target DNA, the biosensing system comprising:
a biosensor comprising a suspension of a hybridization buffer containing dispersed gold nanoparticles, sodium chloride, and single-stranded DNA probes configured to undergo DNA hybridization with the target DNA; and
a laser configured to direct a beam of near-infrared radiation into the biosensor, wherein the beam of near-infrared radiation is configured to induce a photothermal effect in any aggregated gold nanoparticles present in the biosensor,
wherein the biosensor comprises 40 milliMolar concentration of sodium chloride.

16. An aggregation-induced quantitative photothermal biosensing method of detecting a target, the method comprising:
irradiating a biosensor containing a sample with near-infrared radiation for a selected time, wherein the biosensor comprises a suspension of a hybridization buffer containing gold nanoparticles, sodium chloride, and single-stranded DNA probes configured to undergo DNA hybridization with a target, and wherein the near-infrared radiation is configured to induce a photothermal effect in any aggregated gold nanoparticles present in the biosensor;
determining a temperature change of the biosensor after irradiating the biosensor with the near-infrared radiation for the selected time;
determining a concentration of the target present in the sample using the temperature change of the biosensor; and
irradiating the suspension at a power density of 5.2 W/cm 2 for an irradiation time, wherein the irradiation time is from about 5 minutes to about 10 minutes.

17. An aggregation-induced quantitative photothermal biosensing method of detecting a target, the method comprising:
irradiating a biosensor containing a sample with near-infrared radiation for a selected time, wherein the biosensor comprises a suspension of a hybridization buffer containing gold nanoparticles, sodium chloride, and single-

Assignees

• Univ Texas

Inventors

• Li Xiujun
• Zhou Wan

Classifications

• G01N27/3278 Primary

  involving nanosized elements, e.g. nanogaps or nanoparticles (nanopores G01N33/48721; magnetic beads G01N27/745) · CPC title

• G01N27/3276

  being a hybridisation with immobilised receptors (using a FET type sensor G01N27/4145; concerning the hybridisation C12Q1/68) · CPC title

• G01N27/3277

  being a redox reaction, e.g. detection by cyclic voltammetry (voltammetry per se G01N27/42, G01N27/48) · CPC title

• B82Y35/00

  Methods or apparatus for measurement or analysis of nanostructures · CPC title

• G01N27/3275 Primary

  Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction · CPC title