scholarly journals Superior Properties and Biomedical Applications of Microorganism-Derived Fluorescent Quantum Dots

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4486
Author(s):  
Mohamed Abdel-Salam ◽  
Basma Omran ◽  
Kathryn Whitehead ◽  
Kwang-Hyun Baek
Keyword(s):  
Quantum Dots ◽  
Biomedical Applications ◽  
Light Emission ◽  
Distinctive Features ◽  
Energy Applications ◽  
Size Dependent ◽  
Microrna Detection ◽  
Wide Range ◽  
Noxious Chemicals ◽  
Physical And Chemical

Quantum dots (QDs) are fluorescent nanocrystals with superb photo-physical properties. Applications of QDs have been exponentially increased during the past decade. They can be employed in several disciplines, including biological, optical, biomedical, engineering, and energy applications. This review highlights the structural composition and distinctive features of QDs, such as resistance to photo-bleaching, wide range of excitations, and size-dependent light emission features. Physical and chemical preparation of QDs have prominent downsides, including high costs, regeneration of hazardous byproducts, and use of external noxious chemicals for capping and stabilization purposes. To eliminate the demerits of these methods, an emphasis on the latest progress of microbial synthesis of QDs by bacteria, yeast, and fungi is introduced. Some of the biomedical applications of QDs are overviewed as well, such as tumor and microRNA detection, drug delivery, photodynamic therapy, and microbial labeling. Challenges facing the microbial fabrication of QDs are discussed with the future prospects to fully maximize the yield of QDs by elucidating the key enzymes intermediating the nucleation and growth of QDs. Exploration of the distribution and mode of action of QDs is required to promote their biomedical applications.

scholarly journals TiO2–Graphene Quantum Dots Nanocomposites for Photocatalysis in Energy and Biomedical Applications

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 319
Author(s):  
Anuja Bokare ◽  
Sowbaranigha Chinnusamy ◽  
Folarin Erogbogbo
Keyword(s):  
Quantum Dots ◽  
Biomedical Applications ◽  
Wearable Sensors ◽  
Graphene Quantum Dots ◽  
Superior Performance ◽  
Synthesis Methods ◽  
Widespread Application ◽  
Wide Range ◽  
Multifunctional Nanocomposites ◽  
Energy Conversion Devices

The focus of current research in material science has shifted from “less efficient” single-component nanomaterials to the superior-performance, next-generation, multifunctional nanocomposites. TiO2 is a widely used benchmark photocatalyst with unique physicochemical properties. However, the large bandgap and massive recombination of photogenerated charge carriers limit its overall photocatalytic efficiency. When TiO2 nanoparticles are modified with graphene quantum dots (GQDs), some significant improvements can be achieved in terms of (i) broadening the light absorption wavelengths, (ii) design of active reaction sites, and (iii) control of the electron-hole (e−-h+) recombination. Accordingly, TiO2-GQDs nanocomposites exhibit promising multifunctionalities in a wide range of fields including, but not limited to, energy, biomedical aids, electronics, and flexible wearable sensors. This review presents some important aspects of TiO2-GQDs nanocomposites as photocatalysts in energy and biomedical applications. These include: (1) structural formulations and synthesis methods of TiO2-GQDs nanocomposites; (2) discourse about the mechanism behind the overall higher photoactivities of these nanocomposites; (3) various characterization techniques which can be used to judge the photocatalytic performance of these nanocomposites, and (4) the application of these nanocomposites in biomedical and energy conversion devices. Although some objectives have been achieved, new challenges still exist and hinder the widespread application of these nanocomposites. These challenges are briefly discussed in the Future Scope section of this review.

Bioconjugates of Luminescent CdSe-ZnS Quantum Dots with Engineered Recombinant Proteins: Novel Self-Assembled Tools for Biosensing

2000 ◽  
Vol 642 ◽  
Author(s):  
Ellen R. Goldman ◽  
Hedi Mattoussi ◽  
Phan T. Tran ◽  
George P. Anderson ◽  
J. Matthew Mauro
Keyword(s):  
Quantum Dots ◽  
Recombinant Proteins ◽  
Self Assembly ◽  
Emission Spectra ◽  
Igg Antibody ◽  
Photo Degradation ◽  
Size Dependent ◽  
Near Ir ◽  
Wide Range

ABSTRACTColloidal semiconductor quantum dots (QDs) are luminescent nanoparticles with size- dependent emission spectra spanning a wide range of wavelengths in the visible and near IR. This property, as well as their higher resistance to photo-degradation compared to organic dye labels, makes QDs potentially suitable for certain biomolecule tagging and multiplexing applications. We describe an electrostatic self-assembly approach for conjugating highly luminescent colloidal CdSe-ZnS core-shell QDs with engineered two-domain recombinant proteins to form conjugates for sensing and imaging applications. The design, preparation, and characterization of high quantum yield IgG antibody-binding protein G bioconjugates using luminescence, electrophoretic gel shift, and affinity assays is reported.

scholarly journals Photoinitiated Polymerization of Hydrogels by Graphene Quantum Dots

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2169
Author(s):  
Yuna Kim ◽  
Jaekwang Song ◽  
Seong Chae Park ◽  
Minchul Ahn ◽  
Myung Jin Park ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Mechanical Strength ◽  
Biomedical Applications ◽  
Contact Lenses ◽  
Graphene Quantum Dots ◽  
Research Fields ◽  
Wide Range ◽  
Stimulus Responsive ◽  
Dual Functions ◽  
Initiation Of Polymerization

As a smart stimulus-responsive material, hydrogel has been investigated extensively in many research fields. However, its mechanical brittleness and low strength have mattered, and conventional photoinitiators used during the polymerization steps exhibit high toxicity, which limits the use of hydrogels in the field of biomedical applications. Here, we address the dual functions of graphene quantum dots (GQDs), one to trigger the synthesis of hydrogel as photoinitiators and the other to improve the mechanical strength of the as-synthesized hydrogel. GQDs embedded in the network effectively generated radicals when exposed to sunlight, leading to the initiation of polymerization, and also played a significant role in improving the mechanical strength of the crosslinked chains. Thus, we expect that the resulting hydrogel incorporated with GQDs would enable a wide range of applications that require biocompatibility as well as higher mechanical strength, including novel hydrogel contact lenses and bioscaffolds for tissue engineering.

scholarly journals New Insight into the Fluorescence Quenching of Nitrogen-Containing Carbonaceous Quantum Dots—From Surface Chemistry to Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2454
Author(s):  
Marek Wiśniewski ◽  
Joanna Czarnecka ◽  
Paulina Bolibok ◽  
Michał Świdziński ◽  
Katarzyna Roszek
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Biomedical Applications ◽  
Bioactive Molecules ◽  
Reduced Form ◽  
Fluorescent Properties ◽  
Efficient Reduction ◽  
Wide Range ◽  
Ph Conditions

Carbon-based quantum dots are widely suggested as fluorescent carriers of drugs, genes or other bioactive molecules. In this work, we thoroughly examine the easy-to-obtain, biocompatible, nitrogen-containing carbonaceous quantum dots (N-CQDs) with stable fluorescent properties that are resistant to wide-range pH changes. Moreover, we explain the mechanism of fluorescence quenching at extreme pH conditions. Our in vitro results indicate that N-CQDs penetrate the cell membrane; however, fluorescence intensity measured inside the cells was lower than expected from carbonaceous dots extracellular concentration decrease. We studied the mechanism of quenching and identified reduced form of β-nicotinamide adenine dinucleotide (NADH) as one of the intracellular quenchers. We proved it experimentally that the elucidated redox process triggers the efficient reduction of amide functionalities to non-fluorescent amines on carbonaceous dots surface. We determined the 5 nm–wide reactive redox zone around the N-CQD surface. The better understanding of fluorescence quenching will help to accurately quantify and dose the internalized carbonaceous quantum dots for biomedical applications.

Probing Near-Infrared Quantum Dots for Imaging and Biomedical Applications

2011 ◽  
Vol 345 ◽  
pp. 3-11 ◽  
Author(s):  
Zi Hao Wang ◽  
Xue Feng Wang ◽  
Han Jiang ◽  
Jing Ding ◽  
Jian Dong Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Biomedical Applications ◽  
Near Infrared ◽  
Light Emission ◽  
Chemical Properties ◽  
Fluorescent Imaging ◽  
Light Emitting ◽  
Photo Stability

As light-emitting nanocrystals, quantum dots (QDs) have created a new realm of bioscience by combining nanomaterials with biology. They also have been a major focus of research and development during the past decade, which will profoundly influence future biological as well as biomedical research. In recent years, near-infrared (NIR) quantum dots have emerged in analytical applications, especially for in vitro and in vivo imaging. The impetus behind such endeavors can be attributed to their unique optical and chemical properties, with size-tunable light emission, high photo stability, and manifold fluorescence colors. In this review, we focus on fluorescent imaging with near-infrared (NIR) quantum dots (QDs) both in vitro and in vivo, and the advantages of QDs and potential problems to their use in practical biomedical applications. The ultimate targets aim at decreasing the cytotoxicity of QDs and the future outlook of QD applications in biomedical fields.

scholarly journals Quantum Dots: An Emerging Tool for Point-of-Care Testing

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1058
Author(s):  
Suchita Singh ◽  
Aksha Dhawan ◽  
Sonali Karhana ◽  
Madhusudan Bhat ◽  
Amit Kumar Dinda
Keyword(s):  
Quantum Dots ◽  
Biomedical Applications ◽  
Bulk Material ◽  
Point Of Care ◽  
Diagnostic Systems ◽  
Point Of Care Testing ◽  
Size Dependent ◽  
Semiconductor Crystals ◽  
Optical And Electronic Properties ◽  
Narrow Emission

Quantum dots (QDs) are semiconductor crystals in the nanodimension having unique optical and electronic properties that differ from bulk material due to quantum mechanics. The QDs have a narrow emission peak, size-dependent emission wavelength, and broad excitation range which can be utilized for diverse biomedical applications such as molecular imaging, biosensing, and diagnostic systems. This article reviews the current developments of biomedical applications of QDs with special reference to point-of-care testing.

Solvent-Ligand Interactions in Colloidal Nanocrystals

2018 ◽  
Author(s):  
Jonathan De Roo ◽  
Nuri Yazdani ◽  
Emile Drijvers ◽  
Alessandro Lauria ◽  
Jorick Maes ◽  
...  
Keyword(s):  
Direct Method ◽  
Line Broadening ◽  
H Nmr ◽  
Size Dependent ◽  
Line Shape Analysis ◽  
Wide Range ◽  
Nanocrystal Synthesis ◽  
Ligand Interactions ◽  
Indispensable Tool ◽  
Theoretical Evidence

<p>Although solvent-ligand interactions play a major role in nanocrystal synthesis, dispersion formulation and assembly, there is currently no direct method to study this. Here we examine the broadening of <sup>1</sup>H NMR resonances associated with bound ligands, and turn this poorly understood descriptor into a tool to assess solvent-ligand interactions. We show that the line broadening has both a homogeneous and a heterogeneous component. The former is nanocrystal-size dependent and the latter results from solvent-ligand interactions. Our model is supported by experimental and theoretical evidence that correlates broad NMR lines with poor ligand solvation. This correlation is found across a wide range of solvents, extending from water to hexane, for both hydrophobic and hydrophilic ligand types, and for a multitude of oxide, sulfide and selenide nanocrystals. Our findings thus put forward NMR line shape analysis as an indispensable tool to form, investigate and manipulate nanocolloids.</p>

Modification of Collagen for Biomedical Applications: A Review of Physical and Chemical Methods

2016 ◽  
Vol 20 (17) ◽  
pp. 1797-1812 ◽  
Author(s):  
Xiaoyue Yu ◽  
Cuie Tang ◽  
Shanbai Xiong ◽  
Qijuan Yuan ◽  
Zhipeng Gu ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Chemical Methods ◽  
Physical And Chemical

Biomedical Applications and Patents on Metallic Nanoparticles

2020 ◽  
Vol 10 ◽  
Author(s):  
Geetanjali Singh ◽  
Pramod Kumar Sharma ◽  
Rishabha Malviya
Keyword(s):  
Metallic Nanoparticles ◽  
Biomedical Applications ◽  
Size Range ◽  
Biomedical Application ◽  
Chemical Reduction ◽  
Chemical Methods ◽  
Future Challenges ◽  
Biological Methods ◽  
Cancer Diagnosis And Therapy ◽  
Physical And Chemical

Aim/Objective: The author writes the manuscript by reviewing the literatures related to the biomedical application of metallic nanoparticles. The term metal nanoparticles are used to describe the nanosized metals with the dimension within the size range of 1-100 nm. Methods: The preparation of metallic nanoparticles and their application is an influential area for research. Among various physical and chemical methods (viz. chemical reduction, thermal decomposition, etc.) for synthesizing silver nanoparticles, biological methods have been suggested as possible eco-friendly alternatives. The synthesis of metallic nanoparticles is having many problems inclusive of solvent toxicity, the formation of hazardous byproducts and consumption of energy. So it is important to design eco-friendly benign procedures for the synthesis of metallic nanoparticles. Results: From the literature survey, we concluded that metallic nanoparticles have applications in the treatment of different diseases. Metallic nanoparticles are having a great advantage in the detection of cancer, diagnosis, and therapy. And it can also have properties such as antifungal, antibacterial, anti-inflammatory, antiviral and anti-angiogenic. Conclusion: In this review, recent upcoming advancement of biomedical application of nanotechnology and their future challenges has been discussed.

Sign in / Sign up

Export Citation Format

Share Document