Antimicrobial silver nano-particles effective at low concentrations

2005 ◽  
Vol 7 (3) ◽  
pp. 13
Keyword(s):  
Nano Particles ◽  
Low Concentrations

scholarly journals Modifications of the PAMONO-Sensor Help to Size and Quantify Low Number of Individual Biological and Non-Biological Nano-Particles

2021 ◽  
Vol 6 (1) ◽  
pp. 26
Author(s):  
Rahat Morad Talukder ◽  
Al Shahriar Hossain Rakib ◽  
Julija Skolnik ◽  
Zohair Usfoor ◽  
Katharina Kaufmann ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Nano Particles ◽  
Label Free ◽  
Specific Detection ◽  
Virus Like Particles ◽  
Low Concentrations ◽  
Challenging Tasks ◽  
Image Area

In a series of recently published works, we demonstrated that the plasmon-assisted microscopy of nano-objects (PAMONO) technique can be successfully employed for the sizing and quantification of single viruses, virus-like particles, microvesicles and charged non-biological particles. This approach enables label-free, but specific detection of biological nano-vesicles. Hence, the sensor, which was built up utilizing plasmon-assisted microscopy, possesses relative versatility and it can be used as a platform for cell-based assays. However, one of the challenging tasks for such a sensor was the ability to reach a homogeneous illumination of the whole surface of the gold sensor slide. Moreover, in order to enable the detection of even relatively low concentrations of nano-particles, the focused image area had to be expanded. Both tasks were solved via modifications of previously described PAMONO-sensor set ups. Taken together, our latest findings can help to develop a research and diagnostic platform based on the principles of the surface plasmon resonance (SPR)-assisted microscopy of nano-objects.

Silicon Micro-Photonic Structure for Ultra-Sensitive Biosensing

2003 ◽  
Vol 797 ◽  
Author(s):  
Bradley Schmidt ◽  
Vilson Almeida ◽  
Christina Manolatou ◽  
Stefan Preble ◽  
Michal Lipson
Keyword(s):  
Nano Particles ◽  
Particle Detection ◽  
Strong Light ◽  
Extinction Cross Section ◽  
Low Concentrations ◽  
Silicon Photonic ◽  
Micron Size ◽  
Planar Silicon ◽  
Single Particle Detection ◽  
Metal Nano Particles

ABSTRACTWe demonstrate a micron-size planar silicon photonic device that is able to detect low concentrations of metal nano-particles approaching single particle detection. This sensitivity is achieved by using strong light confining structures that enhance the extinction cross-section of metal nano-particles by orders of magnitude. Structures were fabricated and measurements of the transmission spectra of the devices demonstrate the detection of 10 nm diameter gold particles resting on the device with a density of fewer than 2 particles per 104 nm2 (the area of the sensing region surface). Using such a device, in a fluidic platform, one could detect the presence of a single metal nano-particle specifically bound to various analytes, enabling ultrasensitive detection of analytes including DNA, RNA, proteins, and antigens.

SYNTHESIS AND MANIPULATION OF WO3 NANO PARTICLES FOR GAS SENSING APPLICATIONS

2012 ◽  
Vol 05 ◽  
pp. 227-233
Author(s):  
Elham kamali Heidari ◽  
Seyed Reza Mahmoodi ◽  
Ehsan Marzbanrad ◽  
Babak Raisi ◽  
Cyrus Zmani
Keyword(s):  
Gas Sensing ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Nano Particles ◽  
Average Particle ◽  
Monoclinic Structure ◽  
Template Removal ◽  
Sensing Applications ◽  
Low Concentrations ◽  
Nanocasting Route

Ultra fine WO 3 nanoparticles were synthesized by nanocasting route, using mesoporous SiO 2 as a template. BET measurements showed a specific surface area of 700m2/gr for synthesized SiO 2 while after impregnation and template removal, this area was reduced to 43m2/gr for WO 3 nanoparticles. HRTEM results showed single crystalline nanoparticles with average particle size of about 5nm possessing a monoclinic structure which is the favorite crystal structure for gas sensing applications. Alternative electric field was applied to align synthesized WO 3 nanoparticles between electrodes. Gas sensing measurements showed that this material has a high sensitivity to very low concentrations of NO 2 at 250°C.

scholarly journals Nano-particle derived from chaetomium cuprem cc3003 against Anthracnose of coffee var. Arabica

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Kanokmedhakul Somdej ◽  
Vilavong Somlit ◽  
Kanokmedhakul Kaunchai ◽  
Kasem Soytong
Keyword(s):  
Research And Development ◽  
Plant Disease ◽  
Colletotrichum Gloeosporioides ◽  
Control Plant ◽  
Lao Pdr ◽  
Nano Particles ◽  
Nano Particle ◽  
Anthracnose Disease ◽  
Low Concentrations ◽  
New Strategies

Colletotrichum gloeosporioides is proved to be a pathogenic isolate causing anthracnose disease on coffee var. Arabica in Lao PDR. Chaetomium cupreum CC3003 inhibits sporulation of C. gloeosporiodes by 42.60 % in 30 days. The tested nano CCH, nano CCE and nano CCM derived from C. cupreum CC3003 significantly inhibits C. gloeosporioides that cause coffee anthracnose at low concentrations of about 3-15 ppm. The tested nano-particles applied to inoculated coffee seedlings significantly reduce coffee anthracnose. Research and development on nano-particles extracted from fungi are necessary to discover new strategies to control plant disease.

Photocatalytic Degradation of Antibacterial Sulfanilamide from Aqueous Solution Using TiO2 Nanocatalyst

2017 ◽  
Vol 46 ◽  
pp. 111-122 ◽  
Author(s):  
Hosein Ghahremani
Keyword(s):  
Photocatalytic Degradation ◽  
Uv Irradiation ◽  
Reaction Rate ◽  
Inorganic Salt ◽  
Uv Light ◽  
Kinetic Constant ◽  
Nano Particles ◽  
Order Kinetic ◽  
First Order ◽  
Low Concentrations

Photocatalytic degradation of sulfanilamide (SNM) as a kind of pollutant agent through titanium dioxide nano particles (TiO2) under UV irradiation was evaluated. The effect of different parameters, such as TiO2 and SNM concentrations, amount of pH, inorganic salt and type of light source on the reaction rate was investigated. The results show that SNM was completely removed from the solution after 60 min under UV irradiation. Furthermore, kinetic studied were performed at 25°C over different ranges of SNM concentrations from 100 to 300 ppm, TiO2 concentrations from 0.05 to 1 gL-1 and pH of suspensions from 3 to 11. In this range of concentration of materials, a Langmuir–Hinshelwood kinetic model can describe the process. An overall pseudo-first order kinetic constant was calculated for sulfanilamide conversion. The optimum TiO2 loading, which provides enough surface area for reaction without irradiation loss due to scattering of UV light, was found to be 0.1gL-1, and SNM concentration was100 ppm. Higher degradation efficiency of SNM was observed at pH=9. Finally, the results of this work proved that photocatalysis of SNM is a promising technology to reduce persistent substances even if they are present in low concentrations.

scholarly journals Larvicidal potential of two silver nano-particles (Moringa oleifera and Ficus exasperata) against laboratory and field strains of Anopheles gambiae (Diptera: Culicidae) in Lagos, Nigeria

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Emmanuel Taiwo Idowu ◽  
Adedapo O. Adeogun ◽  
Luqman A. Adams ◽  
Modupe A. Yusuf ◽  
Olawale W. Salami ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Moringa Oleifera ◽  
Nano Particles ◽  
Ag Nps ◽  
Anopheles Gambiae S.S ◽  
Post Exposure ◽  
Relative Safety ◽  
Low Concentrations ◽  
Vis Spectroscopy ◽  
Significant Difference

Abstract Background The interest in larvicides of plant origin is generally renewed in vector control because of their safety compared to synthetic larvicides. However, there are concerns about the relative safety dose of these phytochemicals on non-target organisms which led to the development of plant derived nanoparticles. In this study, we examined the bioefficacy of low doses of two green synthesized nanoparticles on immature stages of Anopheles mosquitoes in Nigeria. Aqueous plants (Moringa oleifera and Ficus exasperata) extracts were used in the biosynthesis. The prepared Ag-NPs were characterizations using Fourier-transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, and scanning electron microscopy (SEM). Third and early fourth instars of known susceptible laboratory strains of Anopheles gambiae s.s. (KISUMU strains) and pyrethroid resistant field strain of An. gambiae were exposed to serial dilutions of 0.25, 0.5, 0.75, 1.0 and 2.5 ppm of each phyto nanoparticles. Moribund and dead larvae were observed after 24 and 48 h post exposure, and the results were analysed with descriptive statistics. Results With the laboratory mosquitoes, Moringa oleifera AgNP effected high mortalities of 88–100% (LC50 = 0.39 ppm; LC95 = 0.62 ppm) at 24 h post exposure except at the lowest concentration, while Ficus exasperate AgNP induced a 32–100% mortality (LC50 = 0.51 ppm; LC95 = 1.15 ppm) except at the lowest concentration. In the field populations, mortality in Moringa oleifera and Ficus exasperata was 23–93% (LC50 = 0.65 ppm; LC95 = 2.28 ppm) and 37–50% (LC50 = 1.51 ppm; LC95 = 391.64 ppm) respectively. There was no significant difference in mortality values between the laboratory and field strains (P < 0.05) at both 24 and 48 h post exposure times. Conclusions Overall, the study demonstrates the bioefficacy and potential use of green synthesized nanoparticles, at very low concentrations for the control of Anopheles larvae even in areas where resistance to the current chemical insecticides have been reported.

scholarly journals EFFECT OF GLOBULAR CARBON ADDITION ON RHEOLOGICAL PROPERTIES OF COAL-WATER SUSPENSION

2018 ◽  
Vol 59 (8) ◽  
pp. 5
Author(s):  
Tatyana Yu. Emelyanova ◽  
Lyudmila V. Kashkina ◽  
Vladimir A. Kulagin ◽  
Olesya P. Stebeleva ◽  
Eleanorа A. Petrakovskaya ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Surface Segregation ◽  
Nano Particles ◽  
Combustion Kinetics ◽  
Concentrated Suspension ◽  
Carbon Particles ◽  
Low Concentrations ◽  
Nano Carbon ◽  
Kinetics Of ◽  
Oxygen Impurities

The physical-mechanical properties was studied for the composite material (the highly concentrated suspension based on distilled water, ultra fine brown coal, nano particles of the globular carbon T-900). It was found that carbon nano particles at low concentrations (0.04, 0.08 2 wt.%) can be dispersing agents. Under certain cavitation modes the surface segregation of oxygen impurities was detected in the nano carbon particles. The combustion kinetics of dispersed phase powder of suspension with the addition of 2 wt.% nano carbon differs from the original coal combustion.

scholarly journals Control of rice blast disease caused by Magnaporthe oryzae by application of antifungal nanomaterials from Emericella nidulans

2021 ◽  
Author(s):  
Kasem Soytong ◽  
Jiaojiao Song ◽  
Somdej Kanokmedhakul
Keyword(s):  
Ethyl Acetate ◽  
Magnaporthe Oryzae ◽  
Crude Extract ◽  
Rice Blast ◽  
Nano Particles ◽  
Blast Disease ◽  
Emericella Nidulans ◽  
Crude Extracts ◽  
Low Concentrations ◽  
Rice Leaves

Metabolites of Emericella nidulans (EN) were separated by chromatographic methods from crude hexane included emericellin and sterigmatocystin, while crude ethyl acetate found demethylsterigmatocystin. These metabolites proved to be antagonistic to Magnaporthe oryzae, the causal agent of rice blast. Crude extracts and nano-particles derived from EN inhibited M. oryzae. The ethyl acetate crude extract derived inhibited M. oryzae with an effective dose (ED<sub>50</sub>) of 66 μg/mL. The nanoparticles showed better inhibition of M. oryzae than crude extracts at low concentrations. Nanoparticles, namely from crude ethyl acetate, crude methanol and crude hexane of EN were active against M. oryzae with ED<sub>50</sub> of 4.2 μg/mL, 4.5 μg/mL, 8.9 μg/mL, respectively. It detected sakuranetin (rate of flow value is 0.09) in nano-EN treated rice leaves. These nanoparticles inhibited M. oryzae and acted as a new elicitor to induce immunity.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

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