Solid Fluorescence Standard Using Quantum Dots

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Solution Overview

Problem

Conventional fluorescence standards, such as chemical dyes and mineral substances, face issues like short-term stability, limited spectral range, high cost, mechanical instability, and poor uniformity, making them unsuitable for long-term calibration and data normalization in scientific instruments.

Innovation Solution

A solid fluorescence standard is developed using a low viscosity, solvent-free, radiation curable adhesive with dispersed quantum dots, which is chemically stable, resistant to photobleaching, and applicable across a broad spectral range, ensuring uniformity and robustness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional chemical fluorescence dyes are used, then they provide good initial fluorescence signals, but they are subject to photobleaching and decay rapidly over time

Engineering Contradiction:
Improvefluorescence signal intensityVSAvoidlong term stability
Core Design Contradiction:
Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The patent changes the chemical composition parameters from organic dyes to inorganic fluorescent materials (quantum dots, fluorescent glass, fluorescent plastic), which fundamentally alters the photostability parameter while maintaining fluorescence intensity. This material substitution resolves the contradiction by providing both strong signals and long-term stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite material system combining fluorescent particles with a curable adhesive matrix. This composite structure embeds the fluorescent material in a stable, protective environment that prevents degradation while maintaining optical properties, thereby achieving both high fluorescence intensity and long-term stability.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If mineral fluorescence standards are used, then they are chemically stable, but they suffer from poor uniformity in bulk material and are fragile

Engineering Contradiction:
Improvechemical stabilityVSAvoiduniformity
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent segments the fluorescent material into discrete particles (quantum dots, fluorescent glass particles, or fluorescent plastic particles) rather than using bulk mineral material. This segmentation allows for uniform distribution within the adhesive matrix, achieving consistent fluorescence across the standard while maintaining chemical stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the physical state and form of the fluorescent material from bulk mineral to dispersed particles in a curable adhesive. This parameter change enables precise control over uniformity and eliminates the fragility issue while preserving chemical stability.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional fluorescent dyes are used, then they are inexpensive and easy to prepare, but they are mechanically, thermally, or chemically unstable and can age or dry out

Engineering Contradiction:
Improveease of preparationVSAvoidmechanical and thermal stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the chemical composition from organic dyes to inorganic fluorescent particles embedded in a curable adhesive matrix. This fundamental material parameter change provides mechanical, thermal, and chemical stability while maintaining ease of preparation through simple mixing and curing processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite system where fluorescent particles are embedded in a curable adhesive that provides mechanical protection and environmental stability. This composite structure maintains ease of manufacture while dramatically improving reliability against aging, drying, and environmental degradation.

Inventive Principle:
Principle #40Composite materials

4Adaptability or versatility

If conventional fluorescent dyes are used, then they can be used within specific spectral ranges, but additional excitation/emission combinations require additional dyes

Engineering Contradiction:
Improvespectral range coverageVSAvoidnumber of dyes required
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs fluorescent materials (particularly quantum dots) that exhibit size-tunable emission properties, allowing a single material system to cover multiple spectral ranges. By adjusting particle size, the same base material can emit across different wavelengths, providing universal coverage for multiple excitation/emission combinations without requiring multiple different dye molecules.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solid fluorescence standard provides long-term stability, resistance to photobleaching, and broad spectral applicability, allowing for consistent calibration and normalization of scientific instruments over extended periods without the need for frequent replacement.

Implementation Method 1

radiation curable adhesive (e.g., a UV curable adhesive)... The adhesive is cured and solidified after being disposed in the sample well

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 2

The basis for fluorescence in these dyes is that the molecules absorb light of a given wavelength range (e.g., UV or visible light) and re-emit a portion of the absorbed energy at a known, different wavelength

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 3

photoluminescent nanocrystal-based reference standards comprising quantum dots

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP3391029B1Solid fluorescence standard
Publication Date: 2023.11.08 BIOFIRE DEFENSE LLC
  • EP3391029B1 patent drawingFigure 1
  • EP3391029B1 patent drawingFigure 2a~2b
  • EP3391029B1 patent drawingFigure 3

AI summary

A solid fluorescence standard that can be used to calibrate and/or normalize a device (e.g., a scientific instrument) that is configured for generating and collecting fluorescence data. A fluorescence standard disclosed herein includes an adhesive (e.g., a low viscosity, substantially optically transparent, solvent-free, radiation curable adhesive, such as, but not limited to, a UV curable adhesive), and a selected quantity of fluorescent particles (e.g., quantum dots) dispersed in the adhesive. The adhesive and the fluorescent particles are mixed together and disposed in a sample well. The adhesive is then cured and solidified, which yields a solid fluorescence standard in the well.