Noble Metal Nano Aggregates Stabilized by Amine DCA Capping
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Solution Overview
Problem
Current gold nano clusters (AuNCs) face challenges in achieving uniform size, thermo-dynamical stability, and biocompatibility, leading to toxicity issues and limited biomedical applications due to autocatalysis, plasmon resonance, and instability at acidic pH, which restricts their use in biological systems and in vivo applications.
Innovation Solution
The development of 10-22 nm spherical nano aggregates of molecular ultra small clusters of noble metals, stabilized by amine or dicarboxyacetone, and capped with mercaptoundeconic acid, which exhibit enhanced fluorescence and stability at acidic pH, avoiding plasmon resonance and toxicity, enabling their use in biomedical applications like UV-β therapy, drug delivery, and bioimaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If small gold nano clusters (1-6 atoms) are synthesized to maintain fluorescence and quantum confinement effect, then fluorescence intensity and quantum confinement effect are improved, but toxicity increases and autocatalysis occurs leading to uncontrolled growth
Solution Approach 1:
The patent uses amine/DCA capping agents as intermediary molecules that bind to the surface of ultra small gold clusters (1-6 atoms). These capping agents serve as mediators that stabilize the clusters, preventing autocatalysis and uncontrolled growth while maintaining the small size necessary for fluorescence and quantum confinement effects. The capping agents reduce toxicity by passivating the reactive cluster surfaces.
2Illumination intensity
If small gold nano clusters are used to maintain fluorescence properties, then fluorescence is improved, but thermo-dynamical stability deteriorates due to autocatalysis and conversion to super critical nucleus
Solution Approach 1:
The patent applies preliminary anti-action by using amine/DCA capping agents that pre-emptively prevent autocatalysis and uncontrolled growth of gold clusters. The capping agents bind to the cluster surfaces before autocatalytic growth can occur, creating a kinetic barrier that stabilizes the ultra small clusters (1-6 atoms) against thermodynamic driving forces for growth and conversion to super critical nucleus.
3Stability of the object's composition
If traditional capping agents are used to stabilize gold nano clusters, then stability is improved, but biocompatibility deteriorates due to toxicity issues
Solution Approach 1:
The patent changes the chemical parameters of the capping agents by using amine/DCA (dicarboxy acetone) groups instead of traditional capping agents. These amine/DCA capping agents provide both stability through strong binding to gold clusters and improved biocompatibility through their biochemical properties. The amine/DCA groups create a biocompatible interface while maintaining cluster stability.
4Measurement precision
If uniform size distribution is achieved to improve biosensing performance, then sensitivity is improved, but manufacturing complexity increases due to precise size control requirements
Solution Approach 1:
The patent employs self-service by designing a synthesis system where amine/DCA capping agents automatically control the size and shape of gold clusters during synthesis. The capping agents self-regulate the growth process through steric and electronic effects, leading to uniform size distribution (10-22 nm) without requiring complex external control mechanisms. This self-organizing approach achieves monodispersity while simplifying the manufacturing process.
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 resulting nano aggregates demonstrate enhanced fluorescence, stability, and biocompatibility, allowing for safe and effective use in biomedical applications, including UV-β therapy, drug delivery, and bioimaging, while avoiding the toxicity issues associated with smaller clusters and traditional capping agents.
Implementation Method 1
The MUSNbNCs are capped with amine/ DCA (dicarboxy acetone) group acting as a steric and kinetic hindrance for core growth suppressing the further autocatalysis
Implementation Method 2
The molecular ultra small clusters in a discrete form and controlled size of these nano aggregates thus shows the quantum confinement effect. Hence, these noble metal nano clusters are having potential applications in biomedical like UV & photo therapy
Implementation Method 3
The 10-22 nm nano aggregates of discrete MUSAuNC's after capping with mercaptoundeconic acid (MUDA) shows increase in fluorescent emission by 6 times and which are stable at 3-4 acidic pH
Data Source
Figure 1~3c
Figure 4a~6b
Figure 7a~9b
AI summary
The present invention discloses size controlled and stabilized nano-aggregates of molecular ultra small clusters of noble metals and a process for the preparation thereof. The present invention discloses single source multicolor noble metal spherical and uniform nano aggregates of 10-22 nm made up of discrete molecular ultra small noble metal (Nb) nanoclusters (MUSNbNC's) of 1-6 atoms. The MUSNbNC's are capped with amine/ DCA (dicarboxy acetone) group acting as a steric and kinetic hindrance for core growth suppressing the further autocatalysis and conversion of super critical nucleus or growth by ripening and formation of nanoparticles and thus having intense fluorescence.