# US 11,299,771 B2 · Enhanced DNA sensing via catalytic aggregation of gold nanoparticles by DNA hybridization chain reaction

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- Number: US 11,299,771 B2
- Document ID: US11299771B2
- Status: Granted
- Kind: B2
- Application number: 15/877,128
- Filed: 2018-01-22
- Published: 2018-08-02
- Granted: 2022-04-12
- Earliest claimed: 2013-03-15
- Assignees: Boise State University
- Applicants: Jeunghoon Lee; Bernard Yurke; Elton Graugnard; Will Hughes; Bert Huttanus
- Inventors: Jeunghoon Lee; Bernard Yurke; Elton Graugnard; Will Hughes; Bert Huttanus
- Web page: https://patentgrep.com/patent/US11299771B2

## CPC

- C12Q 1/682: Signal amplification
- C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES

## Abstract

The present invention provides compositions and methods for colorimetric detection schemes for detecting a variety of biomolecules. The compositions and methods employ DNA hybridization chain reaction for catalytic aggregation of gold nanoparticles. In this catalytic aggregation scheme, a single target DNA strand triggers the formation of multiple inter-particle linkages in contrast to the single linkage formed in conventional direct aggregation schemes.

## Claims

### Claim 1

A kit comprising:
a first gold nanoparticle comprising a first linker sequence which will hybridize to a contiguous target sequence a′ and b′, wherein said first linker sequence has a thiol group on the 3′ or 5′ end, and comprises: (i) a sequence a which is the complement of said target sequence a′, (ii) sequence b which is the complement of said target sequence b′, (iii) a b′ sequence, and (iv) a hairpin loop with sequence c which is formed by hybridization of sequences b and b′ in absence of said target sequence a′ and b′; and
a second gold nanoparticle comprising a second linker sequence, wherein said second linker sequence will hybridize to a contiguous target sequence a′ and b′ and comprises (i) the complement of said target sequence b′, (ii) a less than full length complement of said target sequence a′, and (iii) the complement of said hairpin loop with sequence c, and does not form a hairpin in the presence or absence of the target sequence, and
optionally, an RNA extractant buffer, a reaction buffer, a negative control sample, a positive control sample, a reaction container, a colorimetric chart, a packaging material, at least one biological sample preservative or additive, or a combination thereof; and
instructions for use in detecting said target sequence.

### Claim 2

A gold nanoparticle aggregate comprising:
(a) a target sequence with continuous sequences a′ and b′;
(b) a gold nanoparticle comprising a spacer group and a first linker, wherein said first linker has a thiol group on the 3′ or 5′ end and is capable of hybridizing to said target, said first linker comprising:
i) sequence a which is the complement of target sequence a′,
ii) sequence b which is the complement of target sequence b′,
iii) a b′ sequence, and
iv) a hairpin loop with sequence c which is formed by hybridization of sequences b and b′ in absence of said target; and
(c) a second linker comprising a complement of the first linker and a complement of said target, wherein in the presence of said target, said first linker aggregates with said second linker, and wherein said second linker does not form a hairpin in the presence or absence of said target.

### Claim 3 (depends on 2)

The gold nanoparticle aggregate of claim 2 wherein said first linker and/or second linker includes a modification to increase stability of the linker sequences.

### Claim 4 (depends on 2)

The gold nanoparticle aggregate of claim 2 wherein said target sequence is approximately 20 nucleotides in length.