scholarly journals Naturally Derived Carbon Dots as Bioimaging Agents

2021 ◽  
Author(s):  
Gangaraju Gedda ◽  
Arun Bhupathi ◽  
V.L.N. Balaji Gupta Tiruveedhi
Keyword(s):  
Green Synthesis ◽  
Contrast Agents ◽  
Carbon Dots ◽  
Multimodal Imaging ◽  
Water Solubility ◽  
Imaging Techniques ◽  
Fluorescence Emission ◽  
Biological Properties ◽  
Synthesis Methods ◽  
High Fluorescence

The recent advances in nanoscience and technology have opened new avenues for carbon-based nanomaterials. Especially, Carbon dots (CDs) have gained significant attention due to their simple, economic and rapid green synthesis. These materials exhibit excellent water solubility, fluorescence emission, high fluorescence quantum yield, Ultraviolet (UV) to Infrared (IR) range absorbance and high bio-compatibility. Therefore, these materials are widely used for various biological applications including bio-imaging. With the integration and doping of surface passive agents and elements, respectively influenced the enhancement of fluorescence property of CDs. Also, the conjugation of receptor-based targeting ligands leads to targeted bioimaging. CDs in combination with other imaging contrast agents lead to the development of novel contrast agents for bimodal imaging and multimodal imaging techniques. The combination of diagnostic CDs with therapeutic agents resulted in the formation of theragnostic CDs for image guided therapies. In this chapter, a comprehensive view on the top-down and bottom–up green synthesis methods for naturally derived CDs discussed. Further, unique physical, chemical, optical and biological properties of CDs described. Finally, fluorescence based bimodal and multimodal imaging techniques also described.

scholarly journals MULTI-FUNCTIONAL CARBON DOTS: A SYSTEMATIC OVERVIEW

2021 ◽  
pp. 1-22
Author(s):  
MUTHADI RADHIKA REDDY ◽  
KUMAR SHIVA GUBBIYAPPA
Keyword(s):  
Gene Therapy ◽  
Carbon Dots ◽  
Biomedical Applications ◽  
Water Solubility ◽  
Scale Up ◽  
Synthesis Methods ◽  
Bio Imaging ◽  
Low Toxicity

Carbon dots (CDs) have emerged as a potential material in the multifarious fields of biomedical applications due to their numerous advantageous properties including tunable fluorescence, water solubility, biocompatibility, low toxicity, small size and ease of modification, inexpensive scale-up production, and versatile conjugation with other targeted nanoparticles. Thus, CDs became a preferable choice in various biomedical applications such as nanocarriers for drugs, therapeutic genes, photo sensitizers, unique electronic, fluorescent, photo luminescent, chemiluminescent, and electro chemiluminescent, drug/gene delivery and optoelectronics properties are what gives them potential in sensing and antibacterial molecules. Further, their potentials have also been verified in multifunctional diagnostic platforms, cellular and bacterial bio-imaging, development of nanomedicine, etc. This present review provides a concise insight into the progress and evolution in the field of carbon dots research with respect to synthesis methods and materials available in bio-imaging, theranostic, cancer, gene therapy, diagnostics, etc. Further, our discussion is extended to explore the role of CDs in nanomedicine and nano theranostic, biotherapy which is the future of biomedicine and also serves to discuss the various properties of carbon dots which allow chemotherapy and gene therapy to be safer and more target-specific, resulting in the reduction of side effects experienced by patients and also the overall increase in patient compliance and quality of life and representative studies on their activities against bacteria, fungi, and viruses reviewed and discussed. This study will thus help biomedical researchers in percuss the potential of CDs to overcome various existing technological challenges.

scholarly journals Synthesis and Optical Characterizations of the Fluorescence Silica Nanoparticles Containing Quantum Dots

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Chu Viet Ha ◽  
Chu Anh Tuan ◽  
Nguyen Thi Bich Ngoc ◽  
Tran Hong Nhung ◽  
Nguyen Quang Liem ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Silica Nanoparticles ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Ammonium Hydroxide ◽  
Sio2 Nanoparticles ◽  
Synthesis Conditions ◽  
High Fluorescence ◽  
Modified Stöber Method ◽  
Fluorescence Material

The quantum dots coated by silica  is fluorescence material class with great biocompatibility, low toxicity and water-solubility, that is suitable for bioapplications. This work presents the synthesis of SiO2 coated CdTe/ZnSe (named CdTe) quantum dots (CdTe@SiO2 nanoparticles) via a wet chemmical route called modified Stöber method. The compounds tetraethylorthosilicate (TEOS) has used as precursors, aminopropyltriethoxysilane (APTES) is  as  electric neutralizer, and ammonium hydroxide is used as catalysts. The size of CdTe@SiO2 nanoparticles was estimated about 70 to 150 nm depending on the quantities of H2O, APTEOS, and catalysts. The emission behaviours of SiO2 coated quantum dots was effected by ratio of substances participating in the reaction and synthesis conditions. with the ratio (by volume) of suitable substances: TEOS:solution of QDs:NH4OH:APTES:H2O being 1.5:1.5x10-2:0.8x10-2:4x10-2:3x10-4:5x10-2, the prepared silica nanoparticles containing quantum dots show high fluorescence emission efficiency, the fluorescence intensity is higher than that of uncoated CdTe/ZnSe quantum dots. This is a positive result in the technique of manufacturing luminescent silica nanoparticles containing quantum dots. The results show an ability to use the CdTe@SiO2 nanoparticles for biological application.

scholarly journals Construction of Thermo-Responsive Elastin-Like Polypeptides (ELPs)-Aggregation-Induced-Emission (AIE) Conjugates for Temperature Sensing

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1725 ◽  
Author(s):  
Zhe Chen ◽  
Zhaoyang Ding ◽  
Guangya Zhang ◽  
Leilei Tian ◽  
Xuanjun Zhang
Keyword(s):  
Fluorescence Intensity ◽  
Gel Electrophoresis ◽  
Emission Spectroscopy ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Amide Bond ◽  
Aggregation Induced Emission ◽  
Bio Imaging ◽  
High Fluorescence Intensity ◽  
High Fluorescence

In this work, an aggregation-induced emission (AIE) molecule (tetraphenylethene derivative, TPE-COOH) was conjugated to elastin-like polypeptides (ELPs40) via an amide bond to form ELPs40-TPE. The successful synthesis of ELPs40-TPE was confirmed by Circular Dichroism spectroscopy, gel electrophoresis, UV-vis absorption, and fluorescence emission spectroscopy. ELPs40-TPE possessed both amphiphilicity and the features of an AIE, and the fluorescence intensity was dependent on the local temperature. The Hela cells imaging indicated that ELPs40-TPE has great potential for bio-imaging applications because of its advantages of high fluorescence intensity, good water-solubility, and remarkable biocompatibility.

scholarly journals Preparation of water-soluble asphalt carbon dots and hyperchromic effect to Cr (VI)

2018 ◽  
Vol 238 ◽  
pp. 02007
Author(s):  
Lijuan Gao ◽  
Jia Sui ◽  
Xiaoqin Qiao ◽  
Chaoshuai Hu ◽  
Xuefei Zhao
Keyword(s):  
Carbon Dots ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Acid Precipitation ◽  
Water Soluble ◽  
Raw Material ◽  
Precipitation Method ◽  
Acid Oxidation ◽  
Excitation Wavelength ◽  
Uv Spectrum

Water-soluble asphalt carbon dots (W-CDs) was prepared from medium - temperature coal tar pitch as raw material, via mixed acid oxidation, alkali solubilization and acid precipitation method. It was observed that as-prepared W-CDs were irregular particles with good water dispersibility and the particle size was controlled by the pH of the acid precipitation solution by a polarizing microscope. Infrared spectroscopy confirmed that the surface of the W-CDs was functionalized by hydrophilic and color-promoting functional groups, which had good water solubility; the thermal weight loss proved to be good thermal stability below 200°C; the fluorescence spectrum proved that the fluorescence emission peak position of the carbon dots appears red shift with increase of excitation wavelength, with fluorescence conversion property, and its emission light intensity decreases, belonging to non-resonant fluorescence type of direct jump fluorescence; UV spectrum proves that the addition of W-CDs can be chromium (VI) CrO42- content The detection limit was increased from milligram to microgram; the molar absorptivity of CrO42- was increased by 4 times. The experimentally optimized W-CDs-ultraviolet-viscometry method for measuring CrO42- conditions: W-CDs to chromium ratio of 8:2, pH of 8, hexamethylenetetramine as a surfactant, and the solution was allowed to stand at room temperature for 45 min.

scholarly journals Plant Part-Derived Carbon Dots for Biosensing

Biosensors ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 68 ◽  
Author(s):  
Muhammad Zulfajri ◽  
Hani Nasser Abdelhamid ◽  
Sri Sudewi ◽  
Sandhiya Dayalan ◽  
Akhtar Rasool ◽  
...  
Keyword(s):  
Optical Properties ◽  
Natural Resources ◽  
Carbon Dots ◽  
Large Scale ◽  
Water Solubility ◽  
Review Literature ◽  
Plant Part ◽  
Synthesis Methods ◽  
Plant Parts ◽  
Material Development

Carbon dots (CDs) are a new cluster of carbon atoms with particle size less than 10 nm. CDs also exhibit interesting fluorescence (FL) properties. CDs are attractive because of their fascinating characteristics including low toxicity, good water solubility, and tremendous biocompatibility. Recently, CDs have been investigated as biosensors for numerous target analytes. Meanwhile, the utilization of cheap and renewable natural resources not only fulfills the pressing requirement for the large-scale synthesis of CDs but also encourages the establishment of sustainable applications. The preparation of CDs using natural resources, i.e., plants, offers several advantages as it is inexpensive, eco-friendly, and highly available in the surroundings. Plant parts are readily available natural resources as the starting materials to produce CDs with different characteristics and attractive applications. Several review articles are now available covering the synthesis, properties, and applications of CDs. However, there is no specific and focused review literature discussing plant part-derived CDs for biosensing applications. To handle this gap, we provide a review of the progress of CDs derived from various plant parts with their synthesis methods, optical properties, and biosensing applications in the last five years. We highlight the synthesis methods and then give an overview of their optical properties and applications as biosensors for various biomolecules and molecules in biological samples. Finally, we discuss some future perspectives for plant part-derived CDs for better material development and applications.

Green synthesis of multimodal ‘OFF–ON’ activatable MRI/optical probes

2016 ◽  
Vol 45 (44) ◽  
pp. 17672-17680 ◽  
Author(s):  
J. Gallo ◽  
N. Vasimalai ◽  
M. T. Fernandez-Arguelles ◽  
M. Bañobre-López
Keyword(s):  
Green Synthesis ◽  
Contrast Agents ◽  
Carbon Dots ◽  
Optical Contrast ◽  
Optical Probes ◽  
Green Protocol ◽  
Optical Contrast Agents ◽  
Redox Responsive ◽  
Multimodal Mri

We report a simple and green protocol for the preparation of redox responsive multimodal MRI/optical contrast agents based on Mn nanosheets and carbon dots.

Metallic Nanoparticle Synthesis by Green Chemistry

2018 ◽  
Vol 11 (6) ◽  
pp. 4287-4294
Author(s):  
Anikate Sood ◽  
Shweta Agarwal
Keyword(s):  
Green Chemistry ◽  
Green Synthesis ◽  
Biomedical Research ◽  
Metallic Nanoparticles ◽  
Nanoparticle Synthesis ◽  
Synthesis Methods ◽  
Metallic Nanoparticle ◽  
Medical Field ◽  
Advantages And Disadvantages ◽  
Gold Silver

Nanotechnology is the most sought field in biomedical research. Metallic nanoparticles have wide applications in the medical field and have gained the attention of various researchers for advanced research for their application in pharmaceutical field. A variety of metallic nanoparticles like gold, silver, platinum, palladium, copper and zinc have been developed so far. There are different methods to synthesize metallic nanoparticles like chemical, physical, and green synthesis methods. Chemical and physical approaches suffer from certain drawbacks whereas green synthesis is emerging as a nontoxic and eco-friendly approach in production of metallic nanoparticles. Green synthesis is further divided into different approaches like synthesis via bacteria, fungi, algae, and plants. These approaches have their own advantages and disadvantages. In this article, we have described various metallic nanoparticles, different modes of green synthesis and brief description about different metabolites present in plant that act as reducing agents in green synthesis of metallic nanoparticles. 

scholarly journals Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susanna Gevorgyan ◽  
Robin Schubert ◽  
Mkrtich Yeranosyan ◽  
Lilit Gabrielyan ◽  
Armen Trchounian ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Royal Jelly ◽  
Fluorescence Emission ◽  
Spherical Particles ◽  
Ag Nps ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Higher Sensitivity

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.

Non-radioactive imaging strategies for in vivo immune cell tracking

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Łukasz Kiraga ◽  
Paulina Kucharzewska ◽  
Damian Strzemecki ◽  
Tomasz P. Rygiel ◽  
Magdalena Król
Keyword(s):  
Diagnostic Imaging ◽  
Contrast Agents ◽  
Cell Tracking ◽  
Immune Cell ◽  
Imaging Techniques ◽  
Diagnostic Technique ◽  
Cell Labeling ◽  
X Ray Imaging ◽  
Disease Study

Abstract In vivo tracking of administered cells chosen for specific disease treatment may be conducted by diagnostic imaging techniques preceded by cell labeling with special contrast agents. The most commonly used agents are those with radioactive properties, however their use in research is often impossible. This review paper focuses on the essential aspect of cell tracking with the exclusion of radioisotope tracers, therefore we compare application of different types of non-radioactive contrast agents (cell tracers), methods of cell labeling and application of various techniques for cell tracking, which are commonly used in preclinical or clinical studies. We discuss diagnostic imaging methods belonging to three groups: (1) Contrast-enhanced X-ray imaging, (2) Magnetic resonance imaging, and (3) Optical imaging. In addition, we present some interesting data from our own research on tracking immune cell with the use of discussed methods. Finally, we introduce an algorithm which may be useful for researchers planning leukocyte targeting studies, which may help to choose the appropriate cell type, contrast agent and diagnostic technique for particular disease study.

Nanobiotechnology: Nature-inspired silver nanoparticles towards green synthesis

2021 ◽  
pp. 0958305X2198988
Author(s):  
Nur Syakirah Rabiha Rosman ◽  
Noor Aniza Harun ◽  
Izwandy Idris ◽  
Wan Iryani Wan Ismail
Keyword(s):  
Electrical Conductivity ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Current Trend ◽  
Biological Properties ◽  
Noble Metal Nanoparticles ◽  
Current Application ◽  
Physical Chemical ◽  
Physical And Chemical

The emergence of technology to produce nanoparticles (1 nm – 100 nm in size) has drawn significant researchers’ interests. Nanoparticles can boost the antimicrobial, catalytic, optical, and electrical conductivity properties, which cannot be achieved by their corresponding bulk. Among other noble metal nanoparticles, silver nanoparticles (AgNPs) have attained a special emphasis in the industry due to their superior physical, chemical, and biological properties, closely linked to their shapes, sizes, and morphologies. Proper knowledge of these NPs is essential to maximise the potential of biosynthesised AgNPs in various applications while mitigating risks to humans and the environment. This paper aims to critically review the global consumption of AgNPs and compare the AgNPs synthesis between conventional methods (physical and chemical) and current trend method (biological). Related work, advantages, and drawbacks are also highlighted. Pertinently, this review extensively discusses the current application of AgNPs in various fields. Lastly, the challenges and prospects of biosynthesised AgNPs, including application safety, oxidation, and stability, commercialisation, and sustainability of resources towards a green environment, were discussed.

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