Raman-Active Nanoparticles with Nano-Star Core for SERS
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Solution Overview
Problem
Current SERS technologies face limitations in detecting biochemical materials of various sizes due to size constraints and fluorescence interference when using visible light, making it difficult to obtain pure Raman spectra.
Innovation Solution
Development of Raman-active nanoparticles with a nano-star shape metal core and shell structure, where a Raman reporter is fixed in a self-assembled monolayer, allowing for enhanced SERS activity and tunable localized surface plasmon resonance across a wide wavelength range, including near-infrared, and protection from external environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hot spot is formed by contact between two plasmon particles, then SERS activity is enhanced, but the detection is limited to very small analytes due to the limited size of the nanogap
Solution Approach 1:
The invention divides the hot spot formation into multiple independent hot spots distributed across the nanoparticle surface rather than relying on a single nanogap between two particles. Each hot spot can independently enhance Raman signals, and the cumulative effect enables detection of larger analytes while maintaining high SERS activity.
Solution Approach 2:
The invention transitions from a one-dimensional nanogap structure (between two particles) to a two-dimensional distribution of hot spots across the nanoparticle surface. This dimensional expansion allows analytes of various sizes to access multiple hot spots, removing the size limitation while preserving enhancement capability.
2Measurement precision
If visible light is used for SERS detection, then Raman scattering is enhanced, but fluorescence interference occurs making it difficult to obtain pure Raman spectrum
Solution Approach 1:
The invention changes the excitation light wavelength parameter from visible light to near-infrared light. This parameter change shifts the excitation to a region where fluorescence interference is minimized, allowing获得 of pure Raman spectra while maintaining SERS enhancement through the nanoparticle's localized surface plasmon resonance in the near-infrared range.
3Measurement precision
If Raman reporter is exposed to external environment, then it can perform SERS detection, but it lacks stability and durability
Solution Approach 1:
The invention embeds the Raman reporter within the nanoparticle structure, specifically positioning it in the hot spot region between the core and shell. This nested configuration protects the Raman reporter from external environmental factors while maintaining its SERS detection capability, thereby improving stability and durability.
Solution Approach 2:
The invention creates a composite nanoparticle structure with a core-shell configuration where the Raman reporter is integrated at the interface. This composite structure combines the protective properties of the shell with the detection capability of the Raman reporter, achieving both stability and functional performance.
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
Enables the analysis of analytes of various sizes without size limitations, reduces fluorescence interference by using near-infrared light, and enhances Raman signals with improved durability and stability of the nanoparticles.
Implementation Method 1
capable of tuning a localized surface plasmon resonance (LSPR) wavelength to a wide extent
Implementation Method 2
Surface-enhanced Raman scattering (hereinafter referred to as 'SERS') spectrometry uses a phenomenon in which the intensity of Raman scattering greatly increases 106 to 108-fold or more when molecules are adsorbed onto a nanostructure surface of a metal
Implementation Method 3
Raman-active nanoparticles having a Raman activity, specifically a surface-enhanced Raman scattering activity
Data Source
AI summary
Provided is a method of preparing Raman-active nanoparticles, which includes a) preparing a metal nanocore having a nano-star shape from a first reaction solution in which a first metal precursor is mixed with a buffer solution; b) fixing a Raman reporter in the metal nanocore; and c) forming a metal shell, which surrounds the nanocore in which the Raman reporter is fixed, from a second reaction solution in which a second metal precursor is mixed with the nanocore in which the Raman reporter is fixed. The Raman reporter has a binding affinity for each of a first metal of the metal nanocore and a second metal of the metal shell.