Fluorescent Nanodiamonds in Biomedical Applications

2018 ◽  
Vol 101 (5) ◽  
pp. 1297-1307 ◽  
Author(s):  
Katarzyna Anna Mitura ◽  
Elżbieta Włodarczyk

Abstract Nanoparticles have an extended surface and a large surface area, which is the ratio of the size of the surface area to the volume. A functionalized surface can give rise to more modifications and therefore allows this nanomaterial to have new properties. Fluorescent molecules contain fluorophore, which is capable of being excited via the absorption of light energy at a specific wavelength and subsequently emitting radiation energy of a longer wavelength. A chemically modified surface of nanodiamond (ND; by carboxylation) demonstrated biocompatibility with DNA, cytochrome C, and antigens. In turn, fluorescent nanodiamonds (FNDs) belong to a group of new nanomaterials. Their surface can be modified by joining functional groups such as carboxyl, hydroxyl, or amino, after which they can be employed as a fluorescence agent. Their fluorescent properties result from defects in the crystal lattice. FNDs reach dimensions of 4–100 nm, have attributes such as photostability, long fluorescence lifetimes (10 ns), and fluorescence emission between 600 and 700 nm. They are also nontoxic, chemically inert, biocompatible, and environmentally harmless. The main purpose of this article was to present the medical applications of various types of modified NDs.

Clay Minerals ◽  
1966 ◽  
Vol 6 (3) ◽  
pp. 219-228 ◽  
Author(s):  
P. G. Rouxhet ◽  
G. W. Brindley

AbstractThe water gained by two micas during a wet-grinding process (extra-water) has been evaluated. It was found to be proportional to the surface area and the amount was about 29 µmoles/m2 for a fluorphlogopite and about 16 µmoles/m2 for a muscovite. This estimation was made possible by eliminating the physically adsorbed water. The material contaminating the surfaces and the constitution water of muscovite were taken into account by the comparison of the two minerals and by the use of infrared spectroscopy in addition to thermovolumetric data. It is thought that the extra-water is related to a disordered and chemically modified surface layer of the particles. The bearing of these results on the nature of illite is indicated.


2021 ◽  
Author(s):  
Vellaichamy Balakumar ◽  
Manivannan Ramalingam ◽  
Chitiphon Chuaicham ◽  
KARTHIKEYAN SEKAR ◽  
K. Sasaki

Hollow porous graphitic carbon nitride (porous CN) was synthesized via a simple tactic method, and the resulting porous CN showed an effectively modified surface area, crystal structure and enhanced photocatalytic...


Adsorption ◽  
2020 ◽  
Vol 26 (7) ◽  
pp. 1083-1091
Author(s):  
Mi Tian ◽  
Sébastien Rochat ◽  
Hamish Fawcett ◽  
Andrew D. Burrows ◽  
Christopher R. Bowen ◽  
...  

Abstract A detailed investigation has been carried out of the pre-polymerisation modification of the polymer of intrinsic microporosity PIM-1 by the addition of two methyl (Me) groups to its spirobisindane unit to create a new chemically modified PIM-1 analogue, termed MePIM. Our work explores the effects of this modification on the porosity of PIM-1 and hence on its gas sorption properties. MePIM was successfully synthesised using either low (338 K) or high (423 K) temperature syntheses. It was observed that introduction of methyl groups to the spirobisindane part of PIM-1 generates additional microporous spaces, which significantly increases both surface area and hydrogen storage capacity. The BET surface area (N2 at 77 K) was increased by ~ 12.5%, resulting in a ~ 25% increase of hydrogen adsorption after modification. MePIM also maintains the advantages of good processability and thermal stability. This work provides new insights on a facile polymer modification that enables enhanced gas sorption properties.


Author(s):  
Jun-Xia Li ◽  
Tian Zhang ◽  
He-Jun Chen ◽  
Zhong-Xiang Du

Abstract A new binary ZnII coordination polymer, [Zn(2-cpa)(H2O)] n (2D-Zn) has been prepared by a 120 °C hydrothermal reaction of zinc(II) sulfate heptahydrate and 2-carboxy phenoxyacetic acid (2-H2cpa) in the presence of potassium hydroxide. Single-crystal X-ray diffraction analysis shows that the ZnII ion is located in a deformed ZnO6 octahedron bonded by one water and three 2-carboxy phenoxyacetate (2-cpa) ligands. The 2-cpa exhibits pentadentate double bridging chelate-μ 3 coordination mode and connects adjacent ZnII ions to generate a corrugated (4,4)-connected layer structure. The structures, conformation of 2-cpa and photoluminescence spectra for 2D-Zn have been carefully analyzed and compared with its two closely related compounds ̶ 1D [Zn(2-cpa)(H2O)] n (1D-Zn) and mononuclear [Zn(2-cpa)(H2O)3] (0D-Zn). The results showed that the conformation of 2-cpa in 2D-Zn has the maximum alteration and the corresponding fluorescence emission peak of 2D-Zn has the largest red-shift of 62 nm compared with that of free 2-H2cpa.


2018 ◽  
Vol 55 (1) ◽  
pp. 63-67
Author(s):  
Monica Florentina Raduly ◽  
Valentin Raditoiu ◽  
Alina Raditoiu ◽  
Luminita Eugenia Wagner ◽  
Viorica Amariutei ◽  
...  

The seven curcumin derivatives were deposited on palygorskite in order to obtain hybrid materials. The fluorescence emission spectra of the obtained materials show a decrease in fluorescence intensity relative to the respective dyes, due to the environments around the dyestuff molecules created in the host matrices. Absorption studies show the best adsorption on the inorganic matrix, for the compounds with the hydroxyl groups. Correlating fluorescence spectra of hybrid materials with the results for absorption spectra of the dyes adsorbtion on the surface of the clay lead to the conclusion that a high percentage of the adsorbed dye had the effect of fluorescence quenching. Thus, it was confirmed that the fluorescent properties of hybrid materials depend on the interactions established between the fluorescent dyestuff and the inorganic network.


2017 ◽  
Vol 47 (2) ◽  
pp. 972
Author(s):  
E. Koutsopoulou ◽  
K. Katsanou ◽  
D. Papoulis ◽  
E. Zagana ◽  
P. Tsolis- Katagas

Therefore, the evaluation of environmental risks associated with a landfill and the effect of landfill surface runoff was investigated. Soil samples were collected in the downstream area of the waste disposal site and their mineralogy was studied. An appraisal of the heavy metal contamination in the area was attempted. Top layers of sediments seem to interact with chemically modified surface runoff waters from the landfill. Heavy metals such as As and Pb were in significant concentrations in the sediments within a distance of 200 m from the site. Anions such as chloride, sulphate and phosphate adsorbed on clay minerals suggest the interaction of sediments with surface runoff from the waste disposal site. Inorganic parameters NH4 + and NO2 - in surface water samples are above or slightly below the guidelines recommended by EE and WHO. The results indicated that environmental monitoring of the landfill is considered essential.


2003 ◽  
Vol 767 ◽  
Author(s):  
Seung-Mahn Lee ◽  
Wonseop Choi ◽  
Valentin Craciun ◽  
Rajiv K. Singh

AbstractChronoamperometry was used to investigate the reaction/passivation kinetics and thickness of the chemically modified surface layer on the copper during chemical mechanical polishing (CMP). The result showed that the reaction/passivation kinetics and the thickness of the chemically modified surface layer are strongly dependent on the chemistry of CMP slurry in the chemical aspect of CMP and play critical keys in the selection of the chemistry and its concentration. BTA and H2O2 enhanced the passivation kinetics, resulting in thinner layer on the copper surface. In addition, the reaction kinetics increased as pH decreased.


2020 ◽  
Vol 11 (37) ◽  
pp. 6029-6036 ◽  
Author(s):  
Qian-Wei Li ◽  
Yi-Xu Su ◽  
Hui Zou ◽  
Yong-Yuan Chen ◽  
Li Zhou ◽  
...  

UV-responsive azobenzene-containing helical copolymers were obtained, and their self-assembly and fluorescent properties were investigated.


2010 ◽  
Vol 8 (4) ◽  
pp. 750-757
Author(s):  
Waldemar Tomaszewski ◽  
Vladimir Gun’ko ◽  
Roman Leboda ◽  
Jadwiga Skubiszewska-Zięba

AbstractSolid phase extraction (SPE) of methoxy- and methylenedioxyamphetamines from diluted aqueous solutions was investigated on carbon and polymeric adsorbents of different textures and chemical compositions. Those adsorbents were applied cartridges packed with three chemically modified carbons prepared from plum stones (initial A2PS, oxidized A2PS-O, and reduced A2PS-H) and commercially available adsorbents (polymeric LiChrolut EN, graphitized Hypercarb and Carboprep). Several factors influence the recovery rates of amphetamine derivatives such as the polarity of adsorbates (free energy of salvation), the specific surface area and surface composition of adsorbents, and the solvent characteristics. Different combinations of these factors affect the recovery rate (R1) for high- and low-surface area adsorbents. The minimal R1 values are observed for an amphetamine derivative at a maximal solvation effect and for a set of amphetamines adsorbed on graphitized carbons.


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