CONJUGATES OF NANO-DIAMOND AND MAGNETIC OR METALLIC PARTICLES

• US 20140191139A1
• Filed: 01/08/2014
• Published: 07/10/2014
• Est. Priority Date: 08/01/2011
• Status: Active Grant

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: ENGLUND, Dirk R.
• Granted Patent: US 9,222,887 B2
• Time in Patent Office: Days
• US Class Current: 250/459.1
• 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: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/643 non-biological material
• CPC Class Codes: G01N 21/6458 Fluorescence microscopy fluorescence microscopes per se G02B21/0076 and G02B21/16
• CPC Class Codes: G01N 22/00 Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more G01N3/00 - G01N17/00, G01N24/00 take precedence
• CPC Class Codes: G01N 33/48728 Investigating individual cells, e.g. by patch clamp, voltage clamp investigating individual particles in general G01N15/10
• CPC Class Codes: G01N 33/54326 Magnetic particles
• CPC Class Codes: G01N 33/585 with a particulate label, e.g. coloured latex
• CPC Class Codes: G01N 33/587 Nanoparticles

Abstract

Techniques for imaging a characteristic of a sample with a plurality of conjugates of diamond-metallic nanoparticles having a nitrogen vacancy center. The plurality of conjugates can be exposed to a sample and the nitrogen vacancy centers can be optically pumped. One or more microwave pulses can be applied to the nitrogen vacancy center, and a fluorescent response can be detected.

Claims

1. A method for imaging a characteristic of a sample, comprising:

providing a plurality of conjugates of diamond-magnetic nanoparticles, one or more of the plurality of conjugates including a diamond nanoparticle having a nitrogen vacancy center;

exposing the plurality of conjugates to the sample;

optically pumping the nitrogen vacancy center;

applying at least one microwave pulse to the nitrogen vacancy center; and

detecting a fluorescent response of the nitrogen vacancy center.

2. The method of claim 0, wherein the providing further comprises providing at least one diamond nanoparticle bonded to a magnetic nanoparticle by a predetermined distance, the predetermined distance corresponding to a radiative enhancement.

3. The method of claim 0, wherein optically pumping includes directing a continuous wave of pump light at approximately 532 nm to the nitrogen vacancy center.

4. The method of claim 0, wherein optically pumping includes applying a pulse of pump light at approximately 532 nm to the nitrogen vacancy center prior to applying the at least one microwave pulse, and applying a pulse of pump light at approximately 532 nm to the nitrogen vacancy center subsequent to applying the at least one microwave pulse.

5. The method of claim 0, wherein the providing further comprises providing a plurality of conjugates including a nitrogen vacancy center having a different orientation with respect to a corresponding magnetic nanoparticle relative to other conjugates, whereby a component of a magnetic field of the magnetic nanoparticle is exerted along an axis of the nitrogen vacancy center, and whereby a m_s=+1 and a m_s=+1 spin sublevel of the nitrogen vacancy center experience Zeeman splitting.

6. The method of claim 5, wherein detecting a fluorescent response further includes detecting emitted photons over area of the sample, the area divided into a set of pixels each corresponding to a subset of the area.

7. The method of claim 6, wherein detecting emitted photons includes, for each pixel:

applying a first microwave pulse at a first frequency, the first frequency tuned to a field splitting frequency of the nitrogen vacancy center of one of the plurality of conjugates, the field splitting frequency corresponding to the m_s=+1 spin sublevel;

measuring a first intensity of a first fluorescent response based on the first frequency;

applying a second microwave pulse at a second frequency, the second frequency tuned to a zero field splitting frequency of the nitrogen vacancy center of the one of the plurality of conjugates;

measuring a second intensity of a second fluorescent response based on the second frequency;

applying at least a third microwave pulse at a second frequency, the third frequency tuned to a field splitting frequency of the nitrogen vacancy center of the one of the plurality of conjugates, the field splitting frequency corresponding to the m_s=−

1 spin sublevel;

measuring at least a third intensity of a third fluorescent response based on the second frequency;

determining a location of the nitrogen vacancy center based on the first, second and third intensities.

8. The method of claim 7, wherein determining the location includes subtracting the first and second intensities from the first intensity.

9. The method of claim 7, wherein the characteristic of the sample is magnetic field and further comprising determining a local magnetic field a the location of the nitrogen vacancy center based on the first, second, and third intensities.

10. The method of claim 0, wherein the providing further comprises providing one or more conjugates bound to a biological molecule.

11. The method of claim 0, wherein the characteristic of the sample is pH concentration, and further comprising determining, based on the fluorescent response, a rate of ionization or reduction of the nitrogen vacancy center.

12. The method of claim 0, wherein the characteristic of the sample is electric field, and further comprising determining, based on the fluorescent response, a rate of switching between different charge states of the nitrogen vacancy center.

13. A nanoparticle diamond-metal conjugate prepared by the method, comprising:

depositing a monolayer of diamond nanoparticles having approximately a predetermined radius on a substrate, one or more of the diamond nanoparticles having a nitrogen vacancy center;

etching the surface of the substrate to a depth greater than the predetermined radius;

depositing a layer of metal having a predetermined thickness over the monolayer of diamond nanoparticles, the predetermined thickness corresponding to a radiative enhancement rate of the nitrogen vacancy center based on the predetermined radius of the diamond nanoparticles; and

transferring the metal-covered diamond nanoparticles to a second substrate.

14. The nanoparticle diamond-metal conjugate of claim 13, wherein the depositing a layer of metal comprises depositing a metal selected from the group consisting of gold, silver, or a combination thereof.

15. The nanoparticle diamond-metal conjugate of claim 13, wherein the depositing a layer of metal comprises depositing a magnetic layer.

16. The nanoparticle diamond-metal conjugate of claim 15, wherein the depositing a layer of metal comprises depositing a metal selected from the group consisting of nickel, cobalt, iron, or chemical compounds thereof.

17. The nanoparticle diamond-metal conjugate of claim 13, wherein depositing a layer of metal includes depositing the layer of metal at an angle.

18. A nanoparticle diamond-metal conjugate prepared by the method, comprising:

preparing a surface of diamond nanoparticles with an acid treatment, one or more of the diamond nanoparticles having a nitrogen vacancy center;

treating the diamond nanoparticles with one or more amino-terminated silanes to provide an amine on the surface of the diamond nanoparticles;

preparing a surface of metal nanoparticles with a molecule, the molecule having an affinity to bond with the amine; and

mixing the diamond nanoparticles and metal nanoparticles in a solution, whereby the molecule of the surface of the metal nanoparticles bonds to the amine of the surface of the diamond nanoparticles, thereby forming a diamond-metal conjugate.

19. The nanoparticle diamond-metal conjugate of claim 18, wherein the treating further comprises selecting an amine with a length corresponding to a radiative enhancement rate of the nitrogen vacancy center.

20. The nanoparticle diamond-metal conjugate of claim 18, wherein the preparing further comprises preparing a surface of metal nanoparticles selected from the group consisting of gold, silver, or a combination thereof.

21. The nanoparticle diamond-metal conjugate of claim 18, wherein the preparing further comprises preparing a surface of magnetic nanoparticles.

22. The nanoparticle diamond-metal conjugate of claim 21, wherein the preparing further comprises preparing a surface of metal nanoparticles selected from the group consisting of nickel, cobalt, iron, or chemical compounds thereof.

23. A nanoparticle diamond-metal conjugate prepared by the method using a DNA strand, comprising:

preparing a surface of diamond nanoparticles with an acid treatment, one or more of the diamond nanoparticles having a nitrogen vacancy center;

adapting the surface of at least one of the diamond nanoparticles to link to a first end of the DNA strand;

providing metal nanoparticles, at least one of the metal nanoparticles adapted to link to a second end of the DNA strand;

mixing the diamond nanoparticles and the metal nanoparticles in solution with at least the DNA strand.

24. The nanoparticle diamond-metal conjugate of claim 23, wherein the DNA strand comprises a DNA strand having a length corresponding to a radiative enhancement rate of the nitrogen vacancy center.

25. The nanoparticle diamond-metal conjugate of claim 23, wherein the providing further comprises providing metal nanoparticles selected from the group consisting of gold, silver, or a combination thereof.

26. The nanoparticle diamond-metal conjugate of claim 23, wherein the providing further comprises providing magnetic nanoparticles.

27. The nanoparticle diamond-metal conjugate of claim 26, wherein the providing further comprises providing metal nanoparticles selected from the group consisting of nickel, cobalt, iron, or chemical compounds thereof.