Water-Soluble Up-Converting Nanoparticles via Dendrimer Surface Modification
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Solution Overview
Problem
Current methods for synthesizing water-soluble colloidal up-converting nanoparticles (UCNPs) are inefficient, as they often rely on supporting ligands that make nanoparticles insoluble in aqueous environments, limiting their biocompatibility and functionalization for biological applications.
Innovation Solution
Dendrimerization of nanoparticle surfaces by linking dendrite or hyperbranched polymers with hydrophilic groups, specifically ionic groups, to enhance solubility and facilitate functionalization, allowing for the creation of fully water-soluble UCNPs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If supporting ligands with hydrophobic tails are used to stabilize UCNPs during synthesis, then crystalline phase control and synthesis yield are improved, but aqueous solubility and biocompatibility deteriorate
Solution Approach 1:
The patent changes the chemical parameters of the surface ligands by replacing hydrophobic supporting ligands with hydrophilic dendritic polymers containing ionic groups. This parameter change transforms the surface properties of UCNPs from hydrophobic to hydrophilic, enabling aqueous solubility while maintaining synthesis efficiency and crystalline phase control.
Solution Approach 2:
The patent creates a composite surface structure by combining dendritic polymer coatings with ionic groups on the UCNP surface. This composite material approach integrates the stabilizing function of supporting ligands with the solubility-enhancing properties of hydrophilic dendrimers, achieving both high synthesis yield and aqueous compatibility.
2Manufacturing precision
If hydrophobic supporting ligands are used to control nanocrystal formation, then crystalline phase purity is improved, but biocompatibility and functionalization capability deteriorate
Solution Approach 1:
The patent changes the surface chemistry parameters from hydrophobic to hydrophilic by introducing dendritic polymers with ionic groups. This parameter transformation maintains the crystalline phase purity achieved during synthesis while adding biocompatibility and functionalization capabilities required for biological applications.
Solution Approach 2:
The dendritic polymer coating acts as an intermediary layer between the hydrophobic UCNP core and the aqueous biological environment. This intermediary maintains the integrity and crystalline phase of the core while providing a hydrophilic, biocompatible interface for biological applications and further functionalization.
3Use of energy by moving object
If conventional multiphoton excitation with organic dye molecules is used, then emission can be achieved, but multiphoton excitation cross-sections are low and photodamage occurs
Solution Approach 1:
The patent changes the excitation mechanism parameters by using UCNPs with lanthanide ions that enable sequential photon absorption via real excited states rather than virtual states. This parameter change increases the multiphoton excitation cross-section by several orders of magnitude compared to organic dyes, allowing efficient emission with lower energy input and reduced photodamage.
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 approach results in highly soluble and functionalizable UCNPs, enabling effective biological imaging and sensing with enhanced solubility and stability, particularly suitable for multiphoton microscopy and pH sensing applications.
Implementation Method 1
dendrimerized by operably linking to a dendrite polymer having a hydrophilic group or a hyperbranched polymer having a hydrophilic group
Implementation Method 2
wherein the hydrophilic group is ionic
Implementation Method 3
UCNPs are capable of converting near-infrared excitation into visible emission via mutiphoton up-conversion processes
Implementation Method 4
The antenna ions transfer excitation energy onto the emitter ions by way of multi-exciton annihilation/sensitization process
Data Source
AI summary
The invention relates to water-soluble nanoparticles and methods for making such nanoparticles. Specifically, the invention relates to dendrimerization to enhance the solubility of nanoparticles.