- CVD of Carbon Nanomaterials: From Graphene Sheets to Graphene Quantum Dots

2015 ◽  
pp. 1000-1033
Keyword(s):  
Quantum Dots ◽  
Carbon Nanomaterials ◽  
Graphene Quantum Dots ◽  
Graphene Sheets

scholarly journals N-Doped Carbon Quantum Dots as Fluorescent Bioimaging Agents

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 789
Author(s):  
Shih-Fu Ou ◽  
Ya-Yun Zheng ◽  
Sin-Jen Lee ◽  
Shyi-Tien Chen ◽  
Chien-Hui Wu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Nanomaterials ◽  
Graphene Quantum Dots ◽  
Carbon Quantum Dots ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Fluorescence Characteristics ◽  
And Staphylococcus Aureus

Graphene quantum dots, carbon nanomaterials with excellent fluorescence characteristics, are advantageous for use in biological systems owing to their small size, non-toxicity, and biocompatibility. We used the hydrothermal method to prepare functional N-doped carbon quantum dots (N-CQDs) from 1,3,6-trinitropyrene and analyzed their ability to fluorescently stain various bacteria. Our results showed that N-CQDs stain the cell septa and membrane of the Gram-negative bacteria Escherichia coli, Salmonellaenteritidis, and Vibrio parahaemolyticus and the Gram-positive bacteria Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus. The optimal concentration of N-CQDs was approximately 500 ppm for Gram-negative bacteria and 1000 ppm for Gram-positive bacteria, and the exposure times varied with bacteria. N-Doped carbon quantum dots have better light stability and higher photobleaching resistance than the commercially available FM4-64. When excited at two different wavelengths, N-CQDs can emit light of both red and green wavelengths, making them ideal for bioimaging. They can also specifically stain Gram-positive and Gram-negative bacterial cell membranes. We developed an inexpensive, relatively easy, and bio-friendly method to synthesize an N-CQD composite. Additionally, they can serve as a universal bacterial membrane-staining dye, with better photobleaching resistance than commercial dyes.

Self-assembled nitrogen-doped graphene quantum dots (N-GQDs) over graphene sheets for superb electro-photocatalytic activity

2019 ◽  
Vol 480 ◽  
pp. 1035-1046 ◽  
Author(s):  
Rabia Riaz ◽  
Mumtaz Ali ◽  
Iftikhar Ali Sahito ◽  
Alvira Ayoub Arbab ◽  
T. Maiyalagan ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Graphene Quantum Dots ◽  
Graphene Sheets ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Self Assembled

scholarly journals Ultrasensitive Detection of Tetracycline Using Boron and Nitrogen Co-Doped Graphene Quantum Dots from Natural Carbon Source as the Paper-Based Nanosensing Probe in Difference Matrices

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1883
Author(s):  
Hai Linh Tran ◽  
Win Darmanto ◽  
Ruey-An Doong
Keyword(s):  
Quantum Dots ◽  
Human Serum ◽  
Carbon Nanomaterials ◽  
Fruit Juice ◽  
Graphene Quantum Dots ◽  
Passion Fruit ◽  
Analytical Performance ◽  
Sensitivity And Selectivity ◽  
Highly Sensitive Detection ◽  
Co Doped

Herein, the boron and nitrogen co-doped 0-dimensional graphene quantum dots (B,N-GQDs) with high quantum yield (QY) were synthesized via microwave-assisted hydrothermal method at 170 °C for 20 min using fresh passion fruit juice and boric acid as the starting materials. The 3–6 layers of B,N-GQDs with mean particle size of 9 ± 1 nm were then used for ultra-sensitive and selective detection of tetracycline in aqueous and biological media. The hybridization of boron and nitrogen atoms into the GQD structures increases the intensity of electronegative, resulting in the enhancement of QY to 50 ± 1%. The B,N-GQDs show their excellent analytical performance on tetracycline determination after 2 min of reaction under an optimal condition at pH 5. The linear range of 0.04–70 µM and with limits of detection (LOD) of 1 nM in phosphate buffer saline (PBS), 1.9 nM in urine and 2.2 nM in human serum are obtained. Moreover, the high selectivity of tetracycline by B,N-GQDs over the other 23 interferences is observed. The π-π interaction and electron donor-acceptor principle play pivotal roles in enhancing the ultra-sensitivity and selectivity of B,N-GQDs toward TC detection. Moreover, the B, N-GQD based paper nanosensor exhibits an excellent analytical performance on visual detection of 0.1–30 µM TC in human serum. Results of this study clearly indicate the feasibility of synthesis of B,N-GQDs derived from passion fruit juice for ultrasensitive tetracycline detection, which can open an avenue to use natural products for the preparation of environmentally benign and biocompatible carbon nanomaterials for highly sensitive detection of drugs, antibiotics, organic compounds and biomarkers.

Review of research of nanocomposites based on graphene quantum dots

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Aleksey E. Kuznetsov
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement ◽  
Carbon Nanomaterials ◽  
Graphene Quantum Dots ◽  
Band Gaps ◽  
Computational Studies ◽  
Significant Interest ◽  
Low Toxicity ◽  
Water Dispersibility ◽  
High Fluorescence

AbstractGraphene quantum dots (GQDs) belong to the vast and versatile family of carbon nanomaterials. Their unique position amongst versatile carbon nanoparticles (NPs) originates from the properties of quantum confinement and edge effects. GQDs are similar to conventional semiconductor QDs due to their tunable band gaps and high photoluminescence activity. However, GQDs have superior characteristics due to their excellent biocompatibility, low toxicity, good water dispersibility, large optical absorptivity, high fluorescence activity and photostability. These properties have generated significant interest in GQDs applications in various fields: nanosensor fabrication, drug delivery, photocatalysis, photovoltaics, and photodynamic therapy. Numerous GQD-based nanocomposites/nanohybrides have been synthesized and/or studied computationally. This review focuses on recent computational studies of various GQD-based nanocomposites/nanohybrides and systems which can be related to them.

scholarly journals Graphene quantum dots: From efficient preparation to safe renal excretion

Nano Research ◽  
2020 ◽  
Vol 14 (3) ◽  
pp. 674-683
Author(s):  
Caroline Hadad ◽  
José Miguel González-Domínguez ◽  
Silvia Armelloni ◽  
Deborah Mattinzoli ◽  
Masami Ikehata ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Nanomaterials ◽  
Renal Excretion ◽  
Graphene Quantum Dots ◽  
Aqueous Solubility ◽  
Therapeutic Agents ◽  
Internalization Mechanism ◽  
Good Biocompatibility

AbstractCarbon nanomaterials offer excellent prospects as therapeutic agents, and among them, graphene quantum dots (GQDs) have gained considerable interest thanks to their aqueous solubility and intrinsic fluorescence, which enable their possible use in theranostic approaches, if their biocompatibility and favorable pharmacokinetic are confirmed. We prepared ultra-small GQDs using an alternative, reproducible, top-down synthesis starting from graphene oxide with a nearly 100% conversion. The materials were tested to assess their safety, demonstrating good biocompatibility and ability in passing the ultrafiltration barrier using an in vitro model. This leads to renal excretion without affecting the kidneys. Moreover, we studied the GQDs in vivo biodistribution confirming their efficient renal clearance, and we demonstrated that the internalization mechanism into podocytes is caveolae-mediated. Therefore, considering the reported characteristics, it appears possible to vehiculate compounds to kidneys by means of GQDs, overcoming problems related to lysosomal degradation.

scholarly journals Advances in Nanomaterials-Based Electrochemical Biosensors for Foodborne Pathogen Detection

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2700
Author(s):  
Ivan Bobrinetskiy ◽  
Marko Radovic ◽  
Francesco Rizzotto ◽  
Priya Vizzini ◽  
Stefan Jaric ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Foodborne Pathogens ◽  
Pathogen Detection ◽  
Carbon Nanomaterials ◽  
Graphene Quantum Dots ◽  
Foodborne Pathogen ◽  
Electrochemical Biosensors ◽  
Reduced Graphene ◽  
Gold Silver ◽  
2D And 3D Nanostructures

Electrochemical biosensors utilizing nanomaterials have received widespread attention in pathogen detection and monitoring. Here, the potential of different nanomaterials and electrochemical technologies is reviewed for the development of novel diagnostic devices for the detection of foodborne pathogens and their biomarkers. The overview covers basic electrochemical methods and means for electrode functionalization, utilization of nanomaterials that include quantum dots, gold, silver and magnetic nanoparticles, carbon nanomaterials (carbon and graphene quantum dots, carbon nanotubes, graphene and reduced graphene oxide, graphene nanoplatelets, laser-induced graphene), metal oxides (nanoparticles, 2D and 3D nanostructures) and other 2D nanomaterials. Moreover, the current and future landscape of synergic effects of nanocomposites combining different nanomaterials is provided to illustrate how the limitations of traditional technologies can be overcome to design rapid, ultrasensitive, specific and affordable biosensors.

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