# US 2014/0193841 A1 · Fluorogenic semiconductor nanocrystals

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- Number: US 2014/0193841 A1
- Document ID: US20140193841A1
- Status: Published application
- Kind: A1
- Application number: 14/124,354
- Filed: 2012-06-07
- Published: 2014-07-10
- Earliest claimed: 2011-06-07
- Assignees: Life Technologies Corporation
- Inventors: Eric Welch; David Bussian; Michael Ignatius; Lawrence Greenfield
- Web page: https://patentgrep.com/patent/US20140193841A1

## CPC

- G01N 33/525: {Multi-layer analytical elements}
- B82Y 15/00: Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
- C09K 11/08: containing inorganic luminescent materials
- G01N 33/581: {with enzyme label (including co-enzymes, co-factors, enzyme inhibitors or substrates)}
- G01N 33/588: {with semiconductor nanocrystal label, e.g. quantum dots}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

Fluorogenic semiconductor nanocrystals and compositions thereof are provided herein, including kits, assay systems and methods for their preparation and use.

## Claims

### Claim 1

A fluorogenic semiconductor nanocrystal, comprising:
a fluorescent semiconductor nanocrystal: and
a quencher group associated with the semiconductor nanocrystal, wherein the fluorescent semiconductor nanocrystal in the absence of the quencher group has an initial fluorescence intensity (F0), and the fluorogenic semiconductor nanocrystal has a quenched fluorescence intensity (FQ), wherein FQ/F0 is less than about 1.0.

### Claim 2 (depends on 1)

The nanocrystal of claim 1, wherein the fluorogenic semiconductor nanocrystal is substantially non-emissive.

### Claim 3 (depends on 1)

The nanocrystal of claim 1, wherein greater than 50 quencher groups are associated with the nanocrystal.

### Claim 4 (depends on 1)

The nanocrystal of claim 1, wherein the quencher group is or comprises a metal source.

### Claim 5 (depends on 1)

The nanocrystal of claim 1, wherein the quencher group is or comprises a transition or non-transition metal ion.

### Claim 6 (depends on 1)

The nanocrystal of claim 1, wherein the quencher group is or comprises a metal ion selected from Cu(I), Cu(II), Ag (I), Hg (I,II), Pb (II), Pb(IV), Fe (II), Fe(III), Co (II), Ni (II), and Cr (I, II, III, IV, V, or VI).

### Claim 7 (depends on 1)

The nanocrystal of claim 1, wherein the quencher group is or comprises an anion selected from S2−, Se2−, F−, Cl−, Br−, I−, Te2−, or As3−, and phoshonate; or an organic ligand comprising a thiol or thiolate group.

### Claim 8 (depends on 1)

The nanocrystal of claim 1, further comprising a hydrophilic layer on the surface of the semiconductor nanocrystal that renders the nanocrystal water-dispersible.

### Claim 9 (depends on 1)

The nanocrystal of claim 1, further comprising a biomolecule linked to the semiconductor nanocrystal, wherein the biomolecule is selected from a nucleotide, an oligonucleotide, a nucleic acid polymer, an amino acid, polypeptide, a protein, a polysaccharide, a lipid, and biotin.

### Claim at position 10

-11. (canceled)

### Claim 12 (depends on 11)

A composition, comprising:
a population of fluorogenic semiconductor nanocrystals according to claim 11; and
an aqueous or organic medium or a solid support, wherein each nanocrystal is associated with the support, if present.

### Claim at position 12

-22. (canceled)

### Claim 23 (depends on 1)

A method of activating a fluorogenic semiconductor nanocrystal, comprising:
a) providing the fluorogenic semiconductor nanocrystal of claim 1;
b) contacting the nanocrystal with an activator, wherein the fluorescence intensity of the fluorogenic semiconductor nanocrystal after contact with the activator increases.

### Claim 24 (depends on 23)

The method of claim 23, wherein the nanocrystal after contact with the activator has an activated fluorescence intensity (FA), wherein FA/FQ is greater than 1.

### Claim 25 (depends on 23)

The method of claim 23, wherein the FA/FQ is 10 or greater.

### Claim 26 (depends on 23)

The method of claim 23, wherein the activator is a reducing agent, oxidizing agent, proton, or metal ion binding compound.

### Claim 27 (depends on 23)

The method of claim 23, wherein the activator is selected from cyanide, nitrile, isonitrile, azide, thiocyanate, amine, imidazole, thiolate, carboxylate, NO, CO, halides, peroxide, ROS, and hydroxide.

### Claim 28 (depends on 23)

The method of claim 23, wherein the activator comprises a cyanide, isonitrile or nitrile source.

### Claim 29 (depends on 23)

The method of claim 23, wherein the activator is a cyanide ion, a cyanide salt or an organocyanide.

### Claim 30 (depends on 23)

The method of claim 23, further comprising contacting the nanocrystal with a cyanogenic substrate capable of releasing an isonitrile or a cyanide group.

### Claim 31

(canceled)

### Claim 32 (depends on 30)

The method of claim 30, wherein the substrate is selected from amygdalin, prunasin, dhurrin, vicianin, linamarin, lotaustralin, cyanohydrins, cyanohydrin esters, cyanohydrin amides, acetone cyanohydrins, mandelonitrile, and acyl cyanides.

### Claim 33

(canceled)

### Claim 34 (depends on 33)

The method of claim 33, wherein the cyanogenic enzyme is a glucosidase.

### Claim 35 (depends on 33)

The method of claim 33, wherein the cyanogenic enzyme is selected from almond β glucosidase, amygdalase, and linamarase.

### Claim 36

(canceled)

### Claim 37 (depends on 1)

A method of detecting the presence of a target analyte in a sample, comprising:
a) providing a cyanogenic substrate capable of releasing a cyanide source;
b) contacting the sample with the fluorogenic semiconductor nanocrystal of claim 1, wherein the nanocrystal is associated with a first binding group;
c) contacting the sample with a second binding group, wherein the second binding group is associated with a cyanogenic enzyme, wherein the first and second binding groups are different, and wherein the first and second binding groups bind to the analyte, if present;
d) contacting the cyanogenic enzyme with the cyanogenic substrate, thereby releasing the cyanide source from the cyanogenic substrate; and
e) detecting fluorescence emission of the fluorogenic semiconductor nanocrystal, wherein an increase in the intensity of fluorescence emission signal indicates the presence of the analyte in the sample.

### Claim at position 28

-40. (canceled)

### Claim 41 (depends on 1)

A fluorogenic assay system, comprising:
a) a fluorogenic semiconductor nanocrystal of claim 1, wherein the nanocrystal is associated with a first binding group;
b) a cyanogenic enzyme associated with a second binding group, wherein the second binding group is different from the binding group, and wherein the first and the second binding groups are associated with an analyte; and
c) a cyanogenic substrate capable of releasing a cyanide source upon contact with the cyanogenic enzyme.

### Claim at position 30

-59. (canceled)