JP-2026076214-A - Solution-based plasmon-specific binding partner assays and metal nanostructures

Abstract

[Problem] The present invention relates to nanostructure-bonding partner conjugates, reaction mixtures, analyte detection devices, and methods for fabricating and using conjugates. [Solution] In particular, the present invention provides a method for detecting a target analyte in a sample, comprising the step of mixing the sample with a first detection conjugate and a second detection conjugate in a solution, wherein the first and second detection conjugates include metal nanostructures linked to binding partners that can specifically bind to the target analyte when it is present in the sample, forming a complex between the first detection conjugate and the analyte and the second detection conjugate, and the change in optical signal during complex formation indicates the presence of the target analyte in the sample. [Selection Diagram] Figure 1

Inventors

• チャン ビンセント
• アンサー サラ アン
• メーラ ラジェシュ ケイ．
• アロン ケネス ピー．

Assignees

• ゾエティス サービシズ リミテッド ライアビリティ カンパニー

Dates

Publication Date

20260511

Application Date

20260115

Priority Date

20170130

Claims (20)

1. A method for detecting a target analyte in a sample, including the following steps: (a) A step of mixing a sample in solution with a first detection conjugate and a second detection conjugate, wherein the first and second detection conjugates include nanostructures linked to binding partners that can specifically bind to a target analyte if present in the sample to form a complex between the first detection conjugate, the analyte, and the second detection conjugate, the nanostructures including a plurality of protrusions, and the average diameter of the nanostructures from tip to tip is at least about 50 nm; (b) Exposing the complex to a light source in the wavelength range within the ultraviolet-visible-infrared spectrum; and (c) Measuring an optical signal from the complex, wherein a change in the optical signal indicates the presence of the target analyte in the sample.
2. The method according to claim 1, wherein the average diameter of the nanostructure is approximately 70 nm.
3. The method according to claim 1, wherein the average diameter of the nanostructure is approximately 90 nm.
4. The method according to claim 1, wherein the mixing step (a) is carried out in the presence of 3-((3-collamidopropyl)dimethylammino)-1-propanesulfonate (CHAPS).
5. The method according to claim 4, wherein CHAPS is present at a concentration of approximately 0.1% w/v to approximately 0.5% w/v.
6. The method according to claim 4, wherein CHAPS is present in the solution at a concentration of approximately 0.2% w/v.
7. The method according to claim 1, wherein the mixing step (a) is carried out in the presence of a polymer material selected from polyethylene glycol (PEG), polyvinylpyrrolidone, gelatin, cellulose, or a combination thereof.
8. The method according to claim 7, wherein the polymer material is selected from the group consisting of methylcellulose, dextran, polyallylamine, polyethyleneimine, polylysine, polyacrylic acid, polyvinyl alcohol, and polyaspartic acid.
9. The method according to claim 7, wherein the polymer material is PEG, and the PEG is present at a concentration of about 0.1% to about 5% w/v.
10. The method according to claim 1, wherein the solution further comprises a viscosity enhancer.
11. The method according to claim 10, wherein the viscosity enhancer is selected from the group consisting of trehalose, maltodextrin, sucrose, sorbitol, mannitol, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), cyclodextrin, methylcellulose, dextran, and ficol.
12. The method according to claim 1, wherein the solution further comprises a salt selected from MgCl₂ and NaSCN.
13. The method according to claim 12, wherein MgCl₂ or NaSCN is present in the solution at a concentration of about 10 mM to about 250 mM.
14. The method according to claim 12, wherein MgCl₂ or NaSCN is present in the solution at a concentration of about 100 mM.
15. The method according to claim 1, wherein the solution further comprises ethylenediaminetetraacetic acid (EDTA) or ethylene glycol bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA).
16. The method according to claim 15, wherein EDTA or EGTA is present in the solution at a concentration of approximately 5 mM to approximately 100 mM.
17. The method according to claim 1, wherein the solution further comprises a Biolipidure® reagent.
18. The method according to claim 17, wherein the Biolipidure® reagent is selected from the group consisting of Biolipidure® reagents 205, 206, 1002, 1201, and 1202.
19. The method according to claim 1, wherein the optical signal is a reflectance spectrum, an absorbance spectrum, a scattering spectrum, or an emission spectrum.
20. The method according to claim 1, wherein the change in the optical signal includes a spectral peak wavelength shift and/or a full spectral profile shift.

Description

Cross-reference of related applications This application claims the benefit of U.S. Provisional Patent Application No. 62/451,932, filed on 30 January 2017, which is incorporated herein by whole reference. Field of Invention The present invention relates to a system and method for detecting a target analyte in a sample. In particular, the present invention provides a localized surface plasmon resonance-based analyte detection system that can detect small amounts of a target analyte in a sample. Background of the Invention Current immunoassays and biomolecular binding assays typically require multiple steps and high-performance equipment to perform the assay. The lack of sensitivity and complexity associated with performing such heterogeneous assays arise from the specific need to separate labeled specific binding partners from unlabeled specific binding partners. Attempts have been made to develop assays based on the localized surface plasmon resonance (LSPR) properties of precious metal nanoparticles (Tokel et al., Chem Rev., Vol. 114: 5728-5752, 2014 (Non-Patent Literature 1)). LSPR is a collective oscillation of electrons in nanometer-sized structures induced by incident light. Metal nanoparticles exhibit a strong electromagnetic response to refractive index changes in their immediate vicinity, and therefore, the shift in the resonance frequency of the nanoparticles can be measured as an indicator of molecular bonding to the nanoparticle surface. While metal nanoparticles, particularly gold nanoparticles, have been used in diagnostic assays to detect bonding events, such assays generally suffer from low sensitivity and cannot be used to quantitatively monitor the kinetics of continuous bonding events. Therefore, an improved assay method is needed that uses a homogeneous format while providing increased sensitivity. Assays utilizing standard experimental techniques such as spectroscopy are also considered desirable. Tokel et al., Chem Rev., Vol. 114: 5728-5752, 2014 This application describes the use of localized surface plasmon resonance (LSPR) techniques for conducting assays involving specific binding partners, including, but not limited to, ligands, receptors, transcription factors, binding DNA elements, antigens, and antibodies. More specifically, this application relates to processes and materials for achieving significant amplification in such assays using nanostructure-binding partner conjugates. In several aspects, this disclosure provides compositions and methods for achieving highly sensitive detection of molecules using LSPR techniques and for minimizing nonspecific binding (NSB) levels in the provided assays. In various embodiments described herein, this application relates to a nanostructure-binding partner conjugate, wherein the nanostructure is a metallic nanostructure comprising multiple spikes. In some embodiments, the nanostructure is a metallic nanostructure having an average diameter of at least 50 nm. In further embodiments, the nanostructure is a metallic nanostructure having an average diameter of about 50 nm to about 120 nm. In some embodiments, this disclosure provides the use of such a metallic nanostructure-binding partner conjugate in solution for qualitatively or quantitatively determining the binding of a specific binding partner. In some embodiments, this disclosure provides a method for generating the conjugate described herein. In one aspect, this disclosure provides a method and composition for detecting a target analyte in a sample, the method comprising the steps of: mixing the sample in solution with a first detection conjugate and a second detection conjugate, wherein the first and second detection conjugates include nanostructures linked to binding partners that can specifically bind to the target analyte in the sample if present, thereby forming a complex between the first detection conjugate and the analyte and the second detection conjugate. In some embodiments, the nanostructures are anisotropic nanostructures comprising a plurality of protrusions on a spherical core, and the average diameter of the nanostructures from tip to tip is at least about 50 nm. In further embodiments, the average diameter of the nanostructures is about 70 nm or about 90 nm. In some embodiments, the nanostructures are spherical nanostructures. In further embodiments, the method further comprises the step of exposing the complex to a light source in the wavelength range within the ultraviolet-visible-infrared spectrum. In yet another embodiment, the method comprises the step of measuring an optical signal from the complex, wherein a change in the optical signal indicates the presence of a target analyte in the sample. In some embodiments, three or more detection conjugates are used. For example, a third, fourth, fifth, or more detection conjugates are added. In some embodiments, each of the detection conjugates can bind to the same target analyte to form a complex. In some embodiments, e