Surfaces coated with target-induced fluorescent compounds for detection of target elements

• US 7,629,179 B2
• Filed: 03/03/2006
• Issued: 12/08/2009
• Est. Priority Date: 03/03/2005
• Status: Expired due to Fees

• Current Assignee: North Dakota State University (US Bancorp)
• Original Assignee: University of North Dakota (North Dakota University System)
• Inventors: Zhao, Xiaojun Julia, Pierce, David T.
• Primary Examiner(s): Gabel; Gailene R
• Assistant Examiner(s): Counts; Gary W
• Application Number:
  US11/368,315
• Publication Number:
  US 20060199281A1
• Time in Patent Office: 1,376 Days
• Field of Search: 435/7.1, 435/7.92, 436/518, 436/523, 436/525, 436 73- 84, 436/164, 436/172
• US Class Current: 436/518
• 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 2021/7786 Fluorescence
• 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 33/54306 Solid-phase reaction mechanisms
• CPC Class Codes: G01N 33/54346 Nanoparticles
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/582 with fluorescent label
• CPC Class Codes: G01N 33/587 Nanoparticles
• CPC Class Codes: Y10S 435/962 Prevention or removal of interfering materials or reactants or other treatment to enhance results, e.g. determining or preventing nonspecific binding

Abstract

Surfaces coated with a target-induced fluorescent compound are used to detect target elements, especially trace elements. The target-induced fluorescent compound does not fluoresce when excited at a specific wavelength until it has bound a target element. The use of these coated surfaces provides several benefits including reduced background for greater sensitivity and eliminating the need to separate target-induced fluorescent compound that has not bound target element from target-induced fluorescent compound that has bound target element. Coated nanoparticles are especially useful for detection of target elements.

Claims

1. A method for direct detection of a trace element, the method comprising:

(a) linking a surface of a nanoparticle with a compound to form a nanoparticle-linked compound, wherein the compound is selected from a group consisting of;

2,3-diaminonapthalene (DAN);

3,3,′

-diaminobenzidine (DAB);

4-[bis(carboxymethyl)-aminomethyl]-3-hydroxy-2-naphthoic acid (DHNA);

acetic acid, 3,3′

-[vinylenebis[(6-hydroxy-m-phenylene)methylenenitrilo]]tetra-, E-(8CI) (BDDS);

8-amino-3,7,-dimethyl-10-phenyl-10H-phenazion-2-ylidene ammonium ion;

3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-5-(2-hydroxyethyl)-4-methylthiazolium (thiamine);

carboxymethyl-[4-[10-(4-dicarboxymethylaminobenzyl)anthracen-9-ylmethyl]phenyl]amino) acetic acid dipotassium salt (CDAPAP); and

NMBDA, wherein NMBDA is a compound of the formula;

2. The method of claim 1, wherein the surface is an outer surface of the nanoparticle.

3. The method of claim 1, wherein a diameter of the nanoparticle measures between about 1 nanometer and about 100,000 nanometers.

4. The method of claim 1, further comprising linking the nanoparticle to a substrate to form a nanoparticle sensor.

5. The method of claim 1, further comprising attaching a capture compound to the surface of the nanoparticle.

6. The method of claim 5, wherein the capture compound comprises biochemical or molecular binding entities, selected from a group consisting of antibodies, antigens, ligands, receptors, nucleotides, peptides, proteins, lectin, enzymes, substrates, or fragments thereof.

7. The method of claim 5, wherein the capture compound captures a binding site on a surface of a cell or tissue.

8. A method for direct detection of a trace element in the presence of an interfering element to produce a desired fluorescent signal, the method comprising:

(a) forming a nanoparticle-linked compound, comprising;

(1) forming a microemulsion containing a first compound;

(2) forming a porous nanoparticle from the microemulsion, the first compound being trapped inside the porous nanoparticle, wherein the first compound is selected from a group consisting of;

2,3-diaminonapthalene (DAN) capable of binding selenium;

3,3,′

-diaminobenzidine (DAB) capable of binding selenium;

4-[bis(carboxymethyl)-aminomethyl]-3-hydroxy-2-naphthoic acid (DHNA) capable of binding beryllium;

acetic acid, 3,3′

-[vinylenebis[(6-hydroxy-m-phenylene)methylenenitrilo]]tetra-, E-(8CI) (BDDS) capable of binding cadmium;

8-amino-3,7,-dimethyl-10-phenyl-10H-phenazion-2-ylidene ammonium ion capable of binding chromium;

3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-5-(2-hydroxyethyl)-4-methylthiazolium (thiamine) capable of binding mercury;

carboxymethyl-[4-[10-(4-dicarboxymethylaminobenzyl)anthracen-9-ylmethyl]phenyl]amino) acetic acid dipotassium salt (CDAPAP) capable of binding zinc; and

NMBDA capable of binding calcium, wherein NMBDA is a compound of the formula;

9. The method of claim 8, wherein a diameter of the porous nanoparticle measures between about 1 nanometer and about 100,000 nanometers.

10. The method of claim 8, further comprising linking the nanoparticle to a substrate to form a nanoparticle sensor.

11. The method of claim 8, wherein the capture compound comprises biochemical or molecular binding entities selected from a group consisting of antibodies, antigens, ligands, receptors, nucleotides, peptides, proteins, lectin, enzymes, substrates, or fragments thereof.