Fluorescent Silica Nanoparticles Core-Shell Architecture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluorescent nanoparticles less than 30 nm with covalently attached organic dyes suffer from fluorescence quenching due to intraparticle energy transfer and non-radiative decay into the silica matrix, limiting their brightness and photostability.
Innovation Solution
The development of core-shell silica nanoparticles with controlled architecture, where a fluorescent core is surrounded by a silica shell, enhancing fluorescence quantum efficiency by adjusting the radiative and non-radiative rates through changes in silica chemistry and particle architecture, resulting in significant brightness enhancement and improved photostability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organic dyes are covalently bound inside silica particles, then the nanoparticles can be specifically conjugated to biological macromolecules, but the fluorescence quantum efficiency is reduced due to quenching
Solution Approach 1:
The nanoparticle is divided into distinct functional segments: a hydrophobic core that accommodates the organic dye molecule and a hydrophilic silica shell that provides conjugation capability. This segmentation allows the dye to be protected from quenching while maintaining biological conjugation ability through the shell's surface groups.
Solution Approach 2:
The silica shell acts as an intermediary between the hydrophobic dye molecule and the aqueous biological environment. It provides a protective barrier that prevents direct contact between the dye and quenching agents while allowing the nanoparticle to be conjugated to biological macromolecules through surface functional groups.
2Adaptability or versatility
If the nanoparticle size is reduced below 30 nm, then the nanoparticles can penetrate biological membranes more effectively, but fluorescence quenching increases due to enhanced intraparticle energy transfer
Solution Approach 1:
The core region is designed with specific local properties (hydrophobicity, porosity) that are optimized for dye accommodation and protection from quenching. This local quality control allows small nanoparticles to maintain high fluorescence brightness despite the reduced size that would normally enhance quenching effects.
3Reliability
If the silica shell is made thicker, then the protection against non-radiative decay is improved, but the radiative rate decreases due to increased distance from the core
Solution Approach 1:
The shell thickness and composition are optimized as critical parameters to achieve the desired balance. By carefully controlling these parameters, the patent achieves sufficient protection against non-radiative decay while maintaining adequate radiative rate for bright fluorescence.
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
The core-shell architecture increases fluorescence quantum efficiency by enhancing the radiative rate and reducing the non-radiative rate, leading to brighter and more stable nanoparticles compared to free dyes, with the homogenous nanoparticle showing the largest quantum efficiency enhancement.
Implementation Method 1
fluorescent monodisperse silica nanoparticles of less than 30 nm with covalently attached organic dyes
Implementation Method 2
The quenching of fluorescence is usually attributed to either intraparticle energy transfer or non-radiative decay into the silica matrix
Data Source
AI summary
The invention generally relates to fluorescent nanoparticles and more specifically to silica-based fluorescent nanoparticles of less than 30 nm with covalently attached organic dyes. The invention provides a fluorescent monodisperse silica nanoparticle comprising fluorophore center core and a silica shell wherein the radiative properties of the nanoparticle are dependent upon the chemistry (composition) of the core and presence of the silica shell. In one aspect of the invention, the core-shell architecture provides an enhancement in fluorescence quantum efficiency. The invention generally provides control of photophysical properties of dye molecules encapsulated within silica particles with sizes down to 30 nm and below. This control is accomplished through changes in silica chemistry and particle architecture on the nanometer size scale and results in significant brightness enhancement compared to free dye.