Biosynthesized Quantum Dots as Improved Biocompatible Tools for Biomedical Applications

2020 ◽  
Vol 27 ◽  
Author(s):  
Keru Shi ◽  
Xinyi Xu ◽  
Hanrui Li ◽  
Hui Xie ◽  
Xueli Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Semiconductor Nanocrystals ◽  
Early Application ◽  
Living Organisms ◽  
Organic Capping ◽  
Metal Ion Detection

: Quantum dots (QDs), whose diameters are often limited to 10 nm, have been of interest to researchers for their unique optical characteristics, which are attributed to quantum confinement. Following their early application in the electrical industry as light-emitting diode materials, semiconductor nanocrystals have continued to show great potential in clinical diagnosis and biomedical applications. The conventional physical and chemical pathways for QD syntheses typically require harsh conditions and hazardous reagents, and these products encounter non-hydrophilic problems due to organic capping ligands when they enter the physiological environment. The natural reducing abilities of living organisms, especially microbes, are then exploited to prepare QDs from available metal precursors. Low-cost and eco-friendly biosynthesis approaches have the potential for further biomedical applications which benefit from the good biocompatibility of protein-coated QDs. The surface biomass offers many binding sites for modifying substances or targeting ligands and so achieving multiple functions through simple and efficient operations. Biosynthetic QDs could function as bioimaging and biolabeling agents because of their luminescence properties similar to those of chemical QDs. In addition, extensive research has been carried out on the antibacterial activity, metal ion detection and bioremediation. As a result, this review details the advanced progress of biomedical applications of biosynthesized QDs and illustrates these principles as clearly as possible.

scholarly journals An Overview of the Recent Developments in Carbon Quantum Dots—Promising Nanomaterials for Metal Ion Detection and (Bio)Molecule Sensing

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 138
Author(s):  
Silvija Šafranko ◽  
Dominik Goman ◽  
Anamarija Stanković ◽  
Martina Medvidović-Kosanović ◽  
Tihomir Moslavac ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Dots ◽  
Metal Ion ◽  
Water Solubility ◽  
Wide Spectrum ◽  
Low Cost ◽  
Chemical Species ◽  
Carbon Quantum Dots ◽  
Recent Developments ◽  
Metal Ion Detection

The fluorescent carbon quantum dots (CQDs) represent an emerging subset of carbonaceous nanomaterials, recently becoming a powerful tool for biosensing, bioimaging, and drug and gene delivery. In general, carbon dots are defined as zero-dimensional (0D), spherical-like nanoparticles with <10 nm in size. Their unique chemical, optical, and electronic properties make CQDs versatile materials for a wide spectrum of applications, mainly for the sensing and biomedical purposes. Due to their good biocompatibility, water solubility, and relatively facile modification, these novel materials have attracted tremendous interest in recent years, which is especially important for nanotechnology and nanoscience expertise. The preparation of the biomass-derived CQDs has attracted growing interest recently due to their low-cost, renewable, and green biomass resources, presenting also the variability of possible modification for the enhancement of CQDs’ properties. This review is primarily focused on the recent developments in carbon dots and their application in the sensing of different chemical species within the last five years. Furthermore, special emphasis has been made regarding the green approaches for obtaining CQDs and nanomaterial characterization toward better understanding the mechanisms of photoluminescent behavior and sensing performance. In addition, some of the challenges and future outlooks in CQDs research have been briefly outlined.

scholarly journals Top-Down N-Doped Carbon Quantum Dots for Multiple Purposes: Heavy Metal Detection and Intracellular Fluorescence

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2249
Author(s):  
Francesca Limosani ◽  
Elvira Maria Bauer ◽  
Daniele Cecchetti ◽  
Stefano Biagioni ◽  
Viviana Orlando ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Metal Ion ◽  
Reaction Times ◽  
Size Control ◽  
Carbon Quantum Dots ◽  
Cell Nuclei ◽  
Top Down ◽  
Hek 293 ◽  
Metal Ion Detection ◽  
Intracellular Fluorescence

In the present study, we successfully synthesized N-doped carbon quantum dots (N-CQDs) using a top-down approach, i.e., hydroxyl radical opening of fullerene with hydrogen peroxide, in basic ambient using ammonia for two different reaction times. The ensuing characterization via dynamic light scattering, SEM, and IR spectroscopy revealed a size control that was dependent on the reaction time, as well as a more pronounced -NH2 functionalization. The N-CQDs were probed for metal ion detection in aqueous solutions and during bioimaging and displayed a Cr3+ and Cu2+ selectivity shift at a higher degree of -NH2 functionalization, as well as HEK-293 cell nuclei marking.

scholarly journals Facile and High-yield Synthesis of N-doped Carbon Quantum Dots from Biomass Quinoa Saponin for the Detection of Co2+

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Cuo Zhou ◽  
Shunwei Wu ◽  
Shenghui Qi ◽  
Weijun Song ◽  
Chunyan Sun
Keyword(s):  
Quantum Dots ◽  
Metal Ion ◽  
Light Emission ◽  
Low Cost ◽  
Carbon Quantum Dots ◽  
High Yield ◽  
Excitation Wavelength ◽  
Uniform Size ◽  
Orthogonal Experiments ◽  
Co2 Detection

Hydrothermal synthesis of carbon quantum dots (CQDs) from natural biomass is a green and sustainable route for CQDs applications in various fields. In this work, the preparation and characterization of CQDs based on quinoa saponin were investigated. The optimum synthetic conditions determined by orthogonal experiments were as follows: 2 g quinoa saponin powder and 0.04 mol ethylenediamine reacted at 200°C for 10 h. The relative fluorescence quantum yield (QY = 22.2%) can be obtained, which is higher than some results reported in the literatures. The prepared CQDs had a small and uniform size (∼2.25 nm) and exhibited excitation wavelength-dependent blue light emission behavior. The CQDs displayed excellent sensitivity for Co2+ detection along with good linear correlation ranging from 20 to 150 µM and the detection limit of 0.49 µM. The CQDs prepared in this experiment were successfully implanted into soybean sprouts for fluorescence imaging. The sprouts could grow healthily even soaked in the CQDs solution for two weeks, demonstrating the low toxicity of the CQDs. The advantages of the CQDs, such as low cost, ease of manufacture, nontoxicity, and stability, have potential applications in many areas such as metal ion detection and biosensing.

scholarly journals Core-shell Semiconductor Nanocrystals: Effect of Composition, Size, Surface Coatings on their Optical Properties, Toxicity and Pharmacokinetics

2017 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Wafa' T. Al-Jamal
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Photodynamic Therapy ◽  
Biomedical Applications ◽  
Semiconductor Nanocrystals ◽  
Organic Dye ◽  
Surface Coatings ◽  
Core Shell ◽  
Biomedical Field

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.

scholarly journals Red Emission Carbon Dots Prepared by 1,4-Diaminonaphthalene for Light-Emitting Diode Application and Metal Ion Detection

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4716
Author(s):  
Yulong An ◽  
Xu Lin ◽  
Zewen Guo ◽  
Qitao Yin ◽  
Yan Li ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Metal Ion ◽  
Light Emitting Diode ◽  
Wide Spectrum ◽  
Red Light ◽  
Light Emitting ◽  
Fluorescence Characteristics ◽  
Metal Ion Detection ◽  
Solvothermal Methods ◽  
Reaction Media

Carbon dots (CDs), as the most important type of carbon materials, have been widely used in many fields because of their unique fluorescence characteristics and excellent properties of biocompatibility. In previous studies, the fluorescence of CDs was mainly concentrated in the blue and green, whereas the red fluorescence was relatively less. Herein, we prepared efficient red-emitting CDs from 1,4-diaminonaphthalene using solvothermal methods. We discussed the effects of different solvothermal solvents on CDs. The results show that CDs prepared with octane and acetone as reaction media have the best fluorescence properties. The CDs dispersed in different organic solvents exhibited tunable emission across a wide spectrum from 427 nm to 679 nm. We further demonstrated the application of red light-emitting diode (LED) optoelectronics and fluorescence detection of Fe3+ in aqueous solution.

Design and development of electrochemical potentiostat circuit for the sensing of toxic cadmium and lead ions in soil

2021 ◽  
Author(s):  
Rajani Katiyar ◽  
Usha Rani KR ◽  
Sindhu TS ◽  
Sneha Jain HD ◽  
Vidhyashree V ◽  
...  
Keyword(s):  
Metal Ion ◽  
Electronic Circuit ◽  
Low Cost ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Electrochemical Analysis ◽  
Lead Ions ◽  
Lead And Cadmium ◽  
Cadmium And Lead ◽  
Metal Ion Detection

Abstract Contamination of heavy metal ions in soils has proved to be a significant concern and it poses many health risks. Conventional methods which was used for the identification and detection of heavy metals were non portable and not suitable for onsite applications. The proposed work is to design a low cost electronic circuit for the detection of cadmium and lead ions in soil sample. A screen printed electrode and a Glassy Carbon electrode are interfaced with a designed circuit for electrochemical analysis. Anodic stripping voltammetry is the theory behind the metal ion detection process. Based on the current peaks observed in voltammetry process, the presence of lead and cadmium in given sample can be determined. A voltage controlled circuit is designed to perform the functions of Ec-Lab which makes this system portable. The results are compared with that of the potentiostat device to evaluate the accuracy of the designed circuit.

Quantum Dot-Sensitized Solar Cells via Integrated Experimental and Modeling Study

2019 ◽  
Vol 16 (2) ◽  
pp. 436-440
Author(s):  
Lekshmi Gangadhar ◽  
Anusha Kannan ◽  
P. K. Praseetha
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Solar Cell ◽  
Quantum Dot ◽  
Low Cost ◽  
Semiconductor Nanocrystals ◽  
Green Energy ◽  
Research Areas ◽  
Sensitized Solar Cells ◽  
Modeling Study

The solar energy is one of the potential renewable green energy source considering the availability of sunlight in abundance and the need for clean and renewable source of energy. Quantum dots are semiconductor nanocrystals having considerable interest in photovoltaic research areas. Cadmium sulfide-sensitized solar cells are synthesized by Chemical bath deposition and titanium nanowires were fabricated by hydrothermal method. The synthesized CdS quantum dots are sensitized to nanoporous TiO2 films to form quantum dots-sensitized solar cell applications. The introduction of TNWs enables the electrolyte to penetrate easily inside the film which increases the interfacial contact between the nanowires, the quantum dots and the electrolyte results in improvement in efficiency of solar cell. The goal of our research is to understand the fundamental physics and performance of quantum dot-sensitized solar cells with improved photoconversion efficiency at the low cost based on selection of TiO2 nanostructures, sensitizers and electrodes through an integrated experimental and modeling study.

Porous carbon quantum dots: one step green synthesis vial-cysteine and applications in metal ion detection

RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2039-2046 ◽  
Author(s):  
Deli Xiao ◽  
Renfeng Pan ◽  
Siqiao Li ◽  
Jia He ◽  
Man Qi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Porous Carbon ◽  
Metal Ion ◽  
Chemical Method ◽  
Carbon Quantum Dots ◽  
Effective Strategy ◽  
Wet Chemical Method ◽  
One Step ◽  
Wet Chemical ◽  
Metal Ion Detection

A bottom-up and wet-chemical method employing l-cysteine as a precursor has been proven to be an effective strategy for producing fluorescent porous CQDs.

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