Water‐Dispersible Gold Nanoclusters: Synthesis Strategies, Optical Properties, and Biological Applications

Author(s):  
Yu Li ◽  
Tingting Zhai ◽  
Jing Chen ◽  
Jiye Shi ◽  
Lihua Wang ◽  
...  
ACS Omega ◽  
2020 ◽  
Vol 5 (36) ◽  
pp. 22702-22707
Author(s):  
Shuxian Zhu ◽  
Xiaoyu Wang ◽  
Yujie Cong ◽  
Lidong Li

2021 ◽  
Author(s):  
◽  
Amane Shiohara

<p>Quantum dots have applications in biomedical fields such as bio-imaging and drug delivery systems. This thesis describes research on silicon and germanium nanoparticles (quantum dots) synthesis and surface modification for biological applications. Purification methods of these quantum dots were also explored. In chapter 6 the application of silica nanoparticles into dry eye diagnosis was studied. The purpose of this research is to contribute the application of nanotechnology into biological fields. The crystalinity of the quantum dots was characterised by Transmission Electron Microscopy (TEM) and Selected Area Electron Diffraction analysis (SAED). The molecules on the surface of the quantum dots were characterised by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR).  Silicon quantum dots were synthesised with a microemulsion system and various types of molecules were attached on the surface of the silicon quantum dots. However, some of the capping molecules which have oxygen atoms tend to form bonds between oxygen and silicon. Therefore, in the later chapter (chapter 4) various chemical reactions were conducted on the molecules attached to the silicon quantum dots. The silicon quantum dots were capped with diene molecules and one of the double bonds was left on the terminal end. The terminal end double bonds were converted to the functional groups which contain oxygen atoms to form peptide bonds. In this way it was confirmed that it can reduce the risk of oxygen atoms to be attached on the surface of the silicon quantum dots. The molecules on the surface of the silicon quantum dots were characterised mainly by FTIR and ¹H NMR. Optical properties and cyto-toxicity of these silicon quantum dots were also measured and analysed depending on the surface molecules.  Two synthetic approaches were taken to produce germanium quantum dots. The first approach was the microemulsion system at room temperature. Different combinations of the surfactant and capping molecules were tested. For the second approach, high temperature bench top system was applied. In this method the bio-friendly molecules which have high boiling points were chosen as capping agents. The surface molecules were characterised by FTIR spectroscopy.  In chapter 6 the synthesis of dye molecules conjugated silica nanoparticles was described. The purpose of this research is to produce biologically safe nanoparticles which can be applied in dry eye diagnosis. Three different dyes were used to conjugate with the silica nanoparticles. Only fluorescein isothiocyanate (FITC) succeeded in conjugating with the nanoparticles. Optical properties of this sample were measured and compared with the free dye molecule. Also the sample was applied in human eyes to analyse the tear film layer.  An overall conclusion and future plans for the research were given in the last chapter.In this chapter, ideas of overcoming the problems and improving the techniques conducted in the research were described.</p>


Nanoscale ◽  
2020 ◽  
Vol 12 (26) ◽  
pp. 14180-14187 ◽  
Author(s):  
Luyan Wu ◽  
Jie Hu ◽  
Qilin Zou ◽  
Yaling Lin ◽  
Decai Huang ◽  
...  

Y3(Al/Ga)5O12:Ce3+,Cr3+,Nd3+ nanocrystals with strong persistent luminescence in the NIR-II spectral region, which are highly desired for bioimaging, have been synthesized by a salt microemulsion method.


2019 ◽  
Vol 21 (43) ◽  
pp. 23916-23921 ◽  
Author(s):  
Martina Perić ◽  
Željka Sanader Maršić ◽  
Isabelle Russier-Antoine ◽  
Hussein Fakhouri ◽  
Franck Bertorelle ◽  
...  

The effects of explicit ligands and of aqueous solvent on optical properties and in particular on the one- and two-photon excitation fluorescence of zwitterion functionalized gold nanoclusters have been studied.


2018 ◽  
Vol 8 (7) ◽  
pp. 1106 ◽  
Author(s):  
Pannaree Srinoi ◽  
Yi-Ting Chen ◽  
Varadee Vittur ◽  
Maria Marquez ◽  
T. Lee

2010 ◽  
Vol 97 (12) ◽  
pp. 123108 ◽  
Author(s):  
G. W. Shu ◽  
T. Y. Chen ◽  
J. L. Shen ◽  
C. A. J. Lin ◽  
W. H. Chang ◽  
...  

2007 ◽  
Vol 1007 ◽  
Author(s):  
Chang Zhong ◽  
Yuping Bao ◽  
Dung M. Vu ◽  
R. Brian Dyer ◽  
Jennifer S. Martinez

ABSTRACTFluorescent metal nanoclusters, which consist of collections of small numbers of noble metal atoms, are of great interest in photochemistry and photophysics due to their strong size-dependent emission. Historically their generation was confined to gaseous and solid phases; however, recently a unique organic/inorganic hybrid materials approach was developed that utilizes dendrimers as templates to protect nanoclusters from solution based fluorescence quenching. These hybrid dendrimer/gold nanoclusters are water-soluble and highly fluorescent. Yet there are several intrinsic deficiencies in their synthetic method: first, NaBH4, a toxic chemical, was used as reducing agent in the reaction; and second, the reaction yield was low due to the concurrent formation of large, non-emissive, gold particles. Here we report a particle-free method to produce dendrimer-encapsulated gold nanoclusters in high-yield. Proof of concept is demonstrated using OH-terminated poly(amidoamine) dendrimer and Au(PX3)3Cl (X = Ph, Me), but the approach can also be extended to the combination of other dendrimers and organic noble metal salts. Our approach yields fluorescent clusters with homogeneous size distribution. These clusters can be transferred to aqueous solution and used directly for biological applications.


2021 ◽  
Vol 10 (4) ◽  
pp. 2742-2749

Polypyrrole conducting polymers have become significant in different biomedical applications, but unfortunately, they are insoluble with poor mechanical properties. A natural soluble polymer (Chitosan) can be used to improve such properties. Chitosan/polypyrrole composites were synthesized by dispersing the different doped amounts of polypyrrole into the chitosan matrix. The physical properties of the synthesized composite films were investigated using different techniques. The results obtained from FTIR, XRD show the electrostatic interaction between chitosan and polypyrrole. UV/Vis analysis implies that the optical band gap of composite films decreases with increasing polypyrrole concentration, which can be assumed to increase the electrical conduction in the composite films.


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