3D Imaging Semiconductor Nanocrystals Depth Tracking

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Solution Overview

Problem

Current semiconductor nanocrystals face challenges in maintaining high fluorescence and stability when transferred from their growth solution to different chemical environments, leading to aggregation and loss of fluorescence, which complicates single-particle tracking and imaging applications.

Innovation Solution

A method and apparatus for high-resolution 3D imaging of semiconductor nanocrystals using a lens-based optical microscope, which involves measuring the radius of nanocrystals in fluorescence images, determining their relative depths, and tracking their location over time with sub-diffraction limited resolution, allowing for precise three-dimensional mapping of biological structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If nanocrystals are transferred from growth solution to aqueous environments for biological applications, then they become suitable for labeling and sensing, but they lose fluorescence and aggregate

Engineering Contradiction:
Improveapplicability to biological environmentsVSAvoidfluorescence stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent employs amphiphilic polymers as intermediary agents that bridge the hydrophobic nanocrystal surface and the hydrophilic aqueous environment. These polymers contain both hydrophobic segments that interact with the nanocrystal surface and hydrophilic segments that interact with water, preventing aggregation while maintaining fluorescence. The polymer forms a protective shell around the nanocrystal, acting as a mediator between incompatible environments.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the surface chemistry parameters of nanocrystals by controlling the composition and structure of organic ligands. By adjusting ligand chain length, polarity, and functional groups, the nanocrystals can be tuned to maintain stability in specific environments. The patent also controls synthesis parameters such as temperature, solvent composition, and reaction time to optimize surface properties for biological applications.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If conventional lens-based optical microscopes are used for imaging, then the system is simple and accessible, but the resolution is limited to approximately half the wavelength of light

Engineering Contradiction:
Improvemicroscope system simplicityVSAvoidspatial resolution
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs computational image processing techniques that analyze the point spread function and apply deconvolution algorithms to reconstruct images with resolution beyond the diffraction limit. By changing the processing parameters and applying mathematical transformations to the captured optical data, the system achieves super-resolution imaging while maintaining the simplicity of conventional microscope hardware.

Inventive Principle:
Principle #35Parameter changes

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 nanometer-scale spatial resolution and precise tracking of semiconductor nanocrystals, providing unprecedented understanding of biological structures and mechanical properties, such as the glycocalyx layer on bovine aortic endothelial cells, with high accuracy and stability.

Implementation Method 1

Semiconductor nanocrystals are photostable fluorophores with narrow emission spectra tunable through visible and near-infrared wavelengths

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

A lens-based optical microscope can provide a resolution only close to half of the wavelength of light, on the order of hundred of nanometers for visible light

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP2193468B1High-resolution 3D imaging of single semiconductor nanocrystals
Publication Date: 2019.03.27 MASSACHUSETTS INST OF TECH
  • EP2193468B1 patent drawingFigure 1~2
  • EP2193468B1 patent drawingFigure 3
  • EP2193468B1 patent drawingFigure 4

AI summary

A method of imaging microscopic objects includes determining the relative depths of two or more semiconductor nanocrystals by analyzing images of the semiconductor nanocrystals at varying z-displacements.