Carbon dots Dotaz Zobrazit nápovědu
The anti-DNA antibodies are produced in patients with autoimmune disease called systemic lupus erythematodes. They can be reactive against double or single stranded DNA or DNA modified with some other molecules. Using the variety of antibodies it is possible to determine the structure of studied DNA. In this work, we used 4 anti-DNA antibodies produced in egg yolk after immunization of hens with DNA-mBSA antigen – anti-dsDNA, anti-ssDNA, afi-dsDNA and afi-ssDNA. The reactivity of these antibodies was evaluated using the dot blot method with different lengths and concentrations of DNA antigen. The most reactive antibodies (anti-ssDNA) were modified with carbon quantum dots synthesized from multiwall carbon nanotubes and this modification was verified by ELISA-like method with fluorescent detection and fluorescence resonance energy transfer between DNA and quantum dots was observed, increasing the sensitivity of the DNA detection.
Interestingly, even though the absorption maximum of prepared capped carbon quantum dots (CQDs) is 210 nm and the emission maximum is 392 nm, using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) with excitation wavelength of 470 nm and long pass emission filter (510 nm) a signal was observed. Application of separation technique reviled presence of two different species, which corresponded to two well-resolved peaks present in the electropherogram. This fact is probably caused by presence of particles of different sizes.
Using of 3D printing technology (acrylonitrile butadiene styrene as material) stratospheric probe (SP) was developed for the purpose of this experiment. Fluorescent behavior of carbon quantum dots (CQDs) in concentration range 0-32 mg.ml-1 was monitored by stratospheric probe and classical fluorescence spectroscopy. Balloon flight lasted 120 minutes. During this time it traveled 90 km. At a height of approximately 40 km there was a rupture of balloon. Thanks to a parachute SP landed in a controlled manner in the wood in the cadastral area of municipality Brusnica (Slovak Republic). It was found that the fluorescence intensity of CQDs changed slightly before and after the flight, however this was caused by the CQDs instability and not by the detector design.
- MeSH
- 3D tisk MeSH
- atmosféra * MeSH
- design vybavení MeSH
- fluorescence * MeSH
- kvantové tečky * MeSH
- uhlík MeSH
- Publikační typ
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Here, we aimed our attention at the synthesis of carbon dots (C-dots) with the ability to interact with DNA to suggest an approach for the detection of DNA damage. Primarily, C-dots modified with amine moieties were synthesized using the one-step microwave pyrolysis of citric acid in the presence of diethylenetriamine. The C-dots showed strong photoluminescence with a quantum yield of 4%. In addition, the C-dots (2.8±0.8nm) possessed a good colloidal stability and exhibited a positive surface charge (ζ=36mV) at a neutral pH. An interaction study of the C-dots and the DNA fragment of λ bacteriophage was performed, and the DNA binding resulted in changes to the photoluminescent and absorption properties of the C-dots. A binding of the C-dots to DNA was also observed as a change to DNA electrophoretic mobility and a decreased ability to intercalate ethidium bromide (EtBr). Moreover, the Förster (or fluorescence) resonance energy transfer (FRET) between the C-dots and EtBr was studied, in which the C-dots serve as an excitation energy donor and the EtBr serves as an acceptor. When DNA was damaged using ultraviolet (UV) radiation (λ=254nm) and hydroxyl radicals, the intensity of the emitted photoluminescence at 612nm significantly decreased. The concept was proved on analysis of the genomic DNA from PC-3 cells and DNA isolated from melanoma tissues.
- MeSH
- biosenzitivní techniky metody MeSH
- DNA analýza genetika MeSH
- kvantové tečky chemie MeSH
- lidé MeSH
- luminiscenční látky chemie MeSH
- nádorové buněčné linie MeSH
- poškození DNA * účinky záření MeSH
- rezonanční přenos fluorescenční energie metody MeSH
- uhlík chemie MeSH
- ultrafialové záření MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The combination of different nanomaterials has been investigated during the past few decades and represents an exciting challenge for the unexpected emerging properties of the resulting nano-hybrids. Spermidine (Spd), a biogenic polyamine, has emerged as a useful functional monomer for the development of carbon quantum dots (CQDs). Herein, an electrostatically stabilized ternary hybrid, constituted of iron oxide-DNA (the core) and spermidine carbon quantum dots (CQDSpds, the shell), was self-assembled and fully characterized. The as-obtained nano-hybrid was tested on HeLa cells to evaluate its biocompatibility as well as cellular uptake. Most importantly, besides being endowed by the magnetic features of the core, it displayed drastically enhanced fluorescence properties in comparison with parent CQDSpds and it is efficiently internalized by HeLa cells. This novel ternary nano-hybrid with multifaceted properties, ranging from fluorescence to superparamagnetism, represents an interesting option for cell tracking.
- MeSH
- biotechnologie MeSH
- fluorescence MeSH
- HeLa buňky MeSH
- kvantové tečky chemie metabolismus MeSH
- lidé MeSH
- nanostruktury chemie MeSH
- polyaminy chemie metabolismus MeSH
- statická elektřina MeSH
- uhlík chemie metabolismus MeSH
- železité sloučeniny chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Carbon quantum dots (CQDs) have great potential to be utilized as an optical sensing probe due to its unique photoluminescence and less toxic properties. This work reports a simple and novel synthesis method of carbon dots via direct acid hydrolysis in presence of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and bovine serum albumin protein (BSA). In this study, fluorescent CQDs were synthesized by using citric acid and ascorbic acid as the source of carbon precursors, which was covered with polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and with bovine serum albumin (BSA), by microwave irradiation. Furthermore, the synthesis parameters as power, reaction time and temperature were studied and quality of prepared CQDs were investigated by spectral methods. Short reaction time (20 min) and temperature from 120 ºC to 140 ºC under microwave irradiation are sufficient to prepare luminescence carbon quantum dots. Absorption spectra and photoluminescence spectra were measured to characterize prepared dots in water solution. The photoluminescence spectra of CQDs doped with different protection compound show the different luminescent and excitation wavelengths starting from 330 nm to 430 nm. Importantly, these CQDs are demonstrated to be excellent bioimaging agents and fluorescent ink due to their stable emission, well dispersibility, low toxicity, long emission life time, and good compatibility with different macromolecules.
- MeSH
- fluorescence MeSH
- kvantové tečky * MeSH
- kyselina askorbová MeSH
- kyselina citronová MeSH
- mikrovlny MeSH
- polyethylenglykoly MeSH
- povidon MeSH
- povrchové vlastnosti * MeSH
- sérový albumin hovězí MeSH
- spektrofotometrie statistika a číselné údaje MeSH
- techniky syntetické chemie MeSH
- teplota MeSH
- uhlík * MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Despite great efforts, the design of antibacterial surfaces is still a challenge. In this work, results of structural, mechanical, cytotoxic and antibacterial activities of hydrophobic carbon quantum dots/polydimethylsiloxane surfaces are presented. Antibacterial action of this surface is based on the generation of reactive oxygen species which cause bacteria damage by oxidative stress. At the same time, this surface was not cytotoxic towards the NIH/3T3 cells. Swelling-encapsulation-shrink method is applied for encapsulation of hydrophobic carbon quantum dots in medical grade silicone-polydimethylsiloxane. XPS and photoluminescence spectroscopy analyses confirm that hydrophobic carbon quantum dots have been encapsulated successfully into polydimethylsiloxane polymer matrix. Based on stress-strain test the improvement of mechanical properties of these nanocomposites is established. It is shown by electron paramagnetic resonance spectroscopy and luminescence method that nanocomposite generates singlet oxygen initiated by 470 nm blue light irradiation. Antibacterial testing shows the nanocomposite in the form of foil kills Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae and is very effective after only a 15 min irradiation.
- MeSH
- dimethylpolysiloxany farmakologie MeSH
- Escherichia coli účinky léků MeSH
- fotochemoterapie metody MeSH
- Klebsiella pneumoniae účinky léků MeSH
- kvantové tečky terapeutické užití MeSH
- myši MeSH
- nanokompozity terapeutické užití MeSH
- povrchové vlastnosti MeSH
- singletový kyslík metabolismus MeSH
- Staphylococcus aureus účinky léků MeSH
- uhlík farmakologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Inhabitation of various types of bacteria on different surfaces causes vital health problems worldwide. In this work, a wound dressing defeating bacterial infection had been fabricated. The antibacterial effect of polycaprolactone and hydrophobic carbon quantum dots (hCQDs) based nanocomposite has been presented. The nanocomposite was fabricated both via solvent casting and electrospinning method. Nanocomposites with and without hCQDs had been investigated. A detailed study on their morphology and surface properties were performed by scanning electron microscopy, atomic force microscopy and Raman spectroscopy. Prepared nanocomposites had been evaluated by the contact angle, UV-Vis spectroscopy, electron paramagnetic resonance spectroscopy, and antibacterial activity. It was found that nanocomposites were able to produce singlet oxygen upon blue light irradiation at 470 nm, and they were effective in the eradication of Gram positive (Staphylococcus aureus, Listeria monocytogenes) and Gram negative (Escherichia coli, Klebsiella pneumoniae) bacteria.
This study illustrates the synthesis of functionalized carbon quantum dots (CQDs) by the one-pot pyrolysis method. The functionalization agent used in CQD synthesis was poly l- lysine (PLL). Various physicochemical techniques were employed to confirm the successful formation of PLLCQD including High resolution transmission electron microscopy (HR-TEM), UV-Vis spectroscopy, fluorescence spectroscopy; Atomic force microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The size of PLLCQD was confirmed by HRTEM and AFM. The synthesized PLLCQD shows bright blue fluorescence and has a quantum yield of 19.35%. The highest emission band was observed at 471nm when excited to 370nm. The prepared PLLCQD exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus with inhibition zone 7-20 mm. The concentrations of 0.9 to 0.1gmL-1 were studied to determine minimum inhibitory concentration (MIC) by the agar well diffusion assay method. MIC of 0.2gml -1 concentration of PLLCQD is achieved. The anti-angiogenic activity of PLLCQD was determined using (Chick Chorioallantoic Membrane) CAM assay. CAM assay is a reliable in -vivo model to study angiogenesis also; many stimulators and inhibitors have been examined by this method. This study proves higher antibacterial efficiency of PLLCQD over non functionalized CQD. PLLCQD was successfully employed in bio-imaging of the bacterial cell through fluorescence microscopy. Further, PLLCQD displayed cytotoxic effect on endothelial cells and inhibited blood vessel formation in the CAM model.
In this study, enhancement of the electrochemical signals of etoposide (ETO) measured by differential pulse voltammetry (DPV) by modifying a glassy carbon electrode (GCE) with carbon quantum dots (CQDs) is demonstrated. In comparison with a bare GCE, the modified GCE exhibited a higher sensitivity towards electrochemical detection of ETO. The lowest limit of detection was observed to be 5 nM ETO. Furthermore, scanning electron microscopy (SEM), fluorescence microscopy (FM), and electrochemical impedance spectroscopy (EIS) were employed for the further study of the working electrode surface after the modification with CQDs. Finally, the GCE modified with CQDs under optimized conditions was used to analyse real samples of ETO in the prostate cancer cell line PC3. After different incubation times (1, 3, 6, 9, 12, 18 and 24 h), these samples were then prepared prior to electrochemical detection by the GCE modified with CQDs. High performance liquid chromatography with an electrochemical detection method was employed to verify the results from the GCE modified with CQDs.
- MeSH
- elektrochemie přístrojové vybavení metody MeSH
- elektrody MeSH
- etoposid analýza chemie farmakologie MeSH
- kvantové tečky chemie MeSH
- lidé MeSH
- limita detekce MeSH
- nádorové buněčné linie MeSH
- povidon chemie MeSH
- sklo chemie MeSH
- uhlík chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
