Silver-Gold Nanoparticle LSPR Sensing for Protein Interaction
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Solution Overview
Problem
Existing methods for studying interactions between molecules are limited to single analytes and require complex microfluidic setups, making them inefficient for measuring interactions between different molecules in solution.
Innovation Solution
A nanoparticle with a silver core coated with a thin layer of gold, featuring specific surface functionalizations to provide colloidal stability, prevent non-specific binding, and enable specific immobilization of proteins, allowing for the measurement of protein-protein interactions using localized surface plasmon resonance (LSPR) spectroscopy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If prior art methods are used to study molecular interactions, then single analyte detection is achieved, but the system requires complicated microfluidic set-ups and is limited to single analytes
Solution Approach 1:
The nanoparticle surface is functionalized with multiple different binding sites that can simultaneously or sequentially bind different analytes (first analyte and second analyte), enabling the same sensor to measure multiple types of molecular interactions without requiring separate microfluidic channels or complex device reconfiguration
Solution Approach 2:
Multiple binding sites for different analytes are integrated onto a single nanoparticle surface, combining the functionality of multiple sensors into one particle. This eliminates the need for separate microfluidic pathways and allows simultaneous measurement of multiple interactions in a simplified setup
2Measurement precision
If silver nanoparticles are used for LSPR sensing, then high refractive-index sensitivity is achieved, but chemical stability in biological solutions is insufficient
Solution Approach 1:
The nanoparticle is constructed as a composite structure with a silver core that provides high LSPR sensitivity and a gold shell that provides chemical stability in biological solutions. This composite structure combines the advantageous properties of both materials, maintaining the optical sensitivity of silver while gaining the stability of gold
Solution Approach 2:
A thin gold shell is deposited over the silver core, creating a protective film that preserves the silver's optical properties while shielding it from chemical degradation in biological environments. The thinness of the shell ensures minimal impact on the LSPR response
3Adaptability or versatility
If nanoparticle surface is functionalized for specific binding, then specific protein immobilization is enabled, but non-specific binding of macromolecules may occur
Solution Approach 1:
The nanoparticle surface exhibits heterogeneous functionalization with distinct regions: specific binding sites (such as Ni-NTA complexes) that selectively bind target proteins with specific tags, and PEGylated regions that provide anti-fouling properties to prevent non-specific binding of other macromolecules. This spatial differentiation of surface properties enables selective recognition while minimizing background interference
4Reliability
If gold coating is applied to silver nanoparticles, then chemical stability and biocompatibility are improved, but optical sensing performance may be reduced
Solution Approach 1:
A thin gold shell is deposited over the silver core, creating a protective film that preserves the silver's optical properties while shielding it from chemical degradation in biological environments. The thinness of the shell ensures minimal impact on the LSPR response
Solution Approach 2:
The thickness of the gold coating is precisely controlled and optimized to maintain the LSPR characteristics of the silver core. By adjusting the coating thickness parameter, the balance between chemical stability and optical performance is optimized, ensuring the gold layer provides protection without significantly dampening the plasmonic response
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables straightforward, low-cost, and modular measurement of protein-protein interactions in solution phase without complex instrumentation, while maintaining high sensitivity and stability in biological buffers.
Implementation Method 1
Localized surface plasmon resonances (LSPR) to study interaction between molecular structures
Implementation Method 2
The first surface functionalization is adapted to provide colloidal stability of the nanoparticle in solvents
Implementation Method 3
The second surface functionalization may include a binding site for a binding partner, for example a binding partner for a poly-histidine tag
Data Source
Figure 1a~3
Figure 4a~6
Figure 7~8
AI summary
The invention relates to a nanoparticle (1) having core (2), a first surface functionalization (4), and a second surface functionalization (5). The core (2) comprises or consists of a metal, preferably silver. An inorganic coating (3) is arranged around the core (2). The coating (3) preferably comprises or consists of gold. The first surface functionalization (4) is adapted to provide colloidal stability of the nanoparticle (1) in, preferably aqueous, solvents (19). The first functionalization (4) substantially prevents non-specific binding of macromolecules (55), in particular macromolecules including proteins, DNA, and/or RNA. The second surface functionalization (5) includes one of a binding site for a binding partner, preferably a binding site for a poly-histidine tag of a biomolecule (55), and a biomolecule, preferably a protein.