scholarly journals Synthesis, Characterization and Evaluation of the Cytotoxicity of Ni-Doped Zn(Se,S) Quantum Dots

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Melissa Cruz-Acuña ◽  
Sonia Bailón-Ruiz ◽  
Carlos R. Marti-Figueroa ◽  
Ricardo Cruz-Acuña ◽  
Oscar J. Perales-Pérez

Quantum dots (QDs) are semiconductor nanocrystals with desirable optical properties for biological applications, such as bioimaging and drug delivery. However, the potential toxicity of these nanostructures in biological systems limits their application. The present work is focused on the synthesis, characterization, and evaluation of the toxicity of water-stable Ni-doped Zn(Se,S) QDs. Also, the study of nondoped nanostructures was included for comparison purposes. Ni-doped nanostructures were produced from zinc chloride and selenide aqueous solutions in presence of 3-mercaptopropionic acid and Ni molar concentration of 0.001 M. In order to evaluate the potential cytoxicity of these doped nanostructures, human pancreatic carcinoma cells (PANC-1) were used as model. The cell viability was monitored in presence of Ni-doped Zn(Se,S) QDs at concentrations ranging from 0 μg/mL to 500 μg/mL and light excited Ni-doped Zn(Se,S) nanostructures were evaluated at 50 μg/mL. Results suggested that Ni-doped Zn(Se,S) nanostructures were completely safe to PANC-1 when concentrations from 0 μg/mL to 500 μg/mL were used, whereas non-doped nanostructures evidenced toxicity at concentrations higher than 200 μg/mL. Also, Ni-doped Zn(Se,S) QDs under light excitation do not evidence toxicity to PANC-1. These findings suggest strongly that Zn(Se,S) nanostructures doped with nickel could be used in a safe manner in light-driving biological applications and drug delivery.

Author(s):  
Subham Jain N ◽  
Preeti S ◽  
Amit B Patil

Background: The nanotechnology which has vast growth in the research field and the outcome product of nanotechnology is nanoparticles. Quantum dots with a size range of 2-10nm represents a new form in nanotechnology materials. It has showed widespread attention in recent years in the field of science and its application in drug delivery. Quantum dots are semiconductor nanocrystals which possess interesting properties and characteristics such as unique optical properties, quantum confinement effect and emit fluorescence on excitation with a light source which makes them a potential candidate for nano-probes and for carriers for biological application. Objective: The objective of the article is to explain the role and application of Quantum dots in drug delivery and its future application in pharmaceutical science and research. This review focuses on drug delivery through Quantum dots and Quantum dots helping nanocarriers for drug delivery. The development of QD nano-carriers for drugs has become a hotspot in the fields of nano-drug research. The Quantum Dot labelled nano-carrier can able to deliver the drugs with fewer side effects and it can able to trace the drug location in the body. Results: The Fluorescent emission of Quantum dots is better than other organic dyes which leads to better drug delivery for cancer or acting as a tag for other drug carriers. Conclusion: Because of emission property of Quantum Dots, it can be said used with other drug carriers and later it can be traced with the help of Quantum Dots. Quantum dots can be said as smart Drug delivery.


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>


Quantum dots (QDs) have shown promising potential to many biomedical and biological applications, mainly in drug delivery or activation and cellular imaging. These semiconductor nanoparticles, QDs, whose particle size is in the range of 2-10 nanometer with unique photo-chemical and -physical properties that are not possessed by any other isolated molecules, have become one of the distinct class of imaging probes and worldwide platforms for manufacturing of multifunctional nanodevices. In this chapter, properties, applications of QDs, and importance in the biomedical field especially in drug delivery is presented.


2020 ◽  
Vol 8 (27) ◽  
pp. 9329-9336
Author(s):  
Nkosingiphile Zikalala ◽  
Sundararajan Parani ◽  
Ncediwe Tsolekile ◽  
Oluwatobi S. Oluwafemi

Green synthesis of Zn–In–S quantum dots and their fluorescence under an ultra violet lamp.


2017 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Wafa' T. Al-Jamal

Quantum dots are semiconducting nanocrystals that exhibit extraordinary optical properties. QD have shown higher photostability compared to standard organic dye type probes. Therefore, they have been heavily explored in the biomedical field. This review will discuss the different approaches to synthesis, solubilise and functionalise QD. Their main biomedical applications in imaging and photodynamic therapy will be highlighted. Finally, QD biodistribution profile and in vivo toxicity will be discussed.


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>


2017 ◽  
Vol 19 (2) ◽  
Author(s):  
Anne S. Schulze ◽  
Isabella Tavernaro ◽  
Friederike Machka ◽  
Olga Dakischew ◽  
Katrin S. Lips ◽  
...  

2010 ◽  
Vol 30 (4) ◽  
pp. 283-301 ◽  
Author(s):  
Onyechi Obonyo ◽  
Emma Fisher ◽  
Mark Edwards ◽  
Dennis Douroumis

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