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Juibari M.M.,Agricultural Biotechnology Research Institute of Iran | Juibari M.M.,Islamic Azad University at Tehran | Yeganeh L.P.,Iranian Biological Resource center | Abbasalizadeh S.,Agricultural Biotechnology Research Institute of Iran | And 6 more authors.
BioNanoScience | Year: 2015

A systematic optimization process for simple and eco-friendly extracellular biosynthesis of gold nanoparticles by a native thermophilic Ureibacillus thermosphaericus strain thermo-BF isolated from geothermal hot springs has been presented. Biosynthesis reactions were conducted using the culture supernatant at different temperatures (60–80 °C) and pH (6–9) with gold ion concentration ranging from 0.001 to 0.1 M. The results obtained showed that pure spherical nanoparticles in the range of 35–75 nm were produced, and the maximum nanoparticle production was achieved using 0.001 M HAuCl4 at 80 °C, pH 9. Genome mining and profiling of the genes encoding bioreducing enzymes in U. hermosphaericus strain thermo-BF revealed evidences indicating sulfur reduction capability of this bacterium. Overall, the findings of this study confirmed the great biocatalyzing potential of the extermophilic U. thermosphaericus strain thermo-BF supernatant for intensified biosynthesis of gold nanoparticle under extreme conditions. © 2015, Springer Science+Business Media New York. Source


Zhaveh S.,Islamic Azad University at Tehran | Mohsenifar A.,Nanozino Co. | Mohsenifar A.,Nanosystems Research Team NRTeam | Beiki M.,Islamic Azad University at Tehran | And 5 more authors.
Industrial Crops and Products | Year: 2015

Herbal essential oils such as Cuminum cyminum are natural antifungal agents consisting of many different volatile compounds. In the present study, encapsulation by chitosan (CS)-caffeic acid (CA) nanogel was used to improve antimicrobial activity and stability of the C. cyminum essential oils against Aspergillus flavus. An encapsulation efficiency of 85% based on the optical density spectra of the essential oil was achieved and as revealed through the release kinetics studies, 78% of the encapsulated oils were released during 1 week. The results obtained indicated that due to the volatility and instability of the oils when exposed to environmental factors, its encapsulation considerably improved its performance. More specifically, the minimum inhibitory concentration of free and encapsulated C. cyminum essential oils against A. flavus under sealed condition were at 650 and 350. ppm, respectively. Moreover, the encapsulated oils performed better (800. ppm), when tested under non-sealed condition while the free oils failed to caused fungal growth inhibition within the concentration range tested (up to 1000. ppm). This finding could be of great significance in medicinal plant remedies in order to achieve improved performance of herbal essential oils at lower concentrations and during longer time frames. © 2015 Elsevier B.V. Source


Mesbah Namini S.M.,Tarbiat Modares University | Mohsenifar A.,Nanosystems Research Team NRTeam | Karami R.,Tarbiat Modares University | Rahmani-Cherati T.,Nanozino | And 4 more authors.
Chemical Papers | Year: 2015

Organophosphorus (OP) compounds are extensively used in agricultural practice for pest management. However, their residues have a long half-life in the ecosystem as well as in the agro-products, posing a serious threat to human and animal health. Aryldialkylphosphatase (EC 3.1.8.1) is widely used in detoxification procedures. In the present study, aryldialkylphosphatase was immobilised on synthesised cross-linked nano-sized gel particles, also known as nanogels, in order to enhance the enzyme's physicochemical properties. Accordingly, a new nanogel consisting of chitosan and myristic acid (CMA nanogel) was synthesised and characterised by way of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The aryldialkylphosphatase-CMA nanogel conjugate was then assayed by FTIR, and its physicochemical characteristics were also investigated. The data obtained from SEM and TEM showed the nanogels to be homogenous spherical particles less than 50 nm in diameter. The proper formation of the nanogel and nanobioconjugate was also confirmed by FTIR spectra. In comparison with the free enzyme, the pH and thermal stability of the aryldialkylphosphatase were enhanced by the covalent immobilisation. Moreover, the immobilised enzyme could maintain approximately half of its activity over more than one month. The kinetic parameters of the aryldialkylphosphatase-CMA nanogel conjugate were also shown to undergo remarkable improvements, hence the synthesised CMA-nanogel could act as a promising support for aryldialkylphosphatase immobilisation. It is suggested that the aryldialkylphosphatase-CMA nanogel could be used for detoxifying paraoxon; a nerve agent. Further clinical experiments are underway. © Institute of Chemistry, Slovak Academy of Sciences 2015. Source


Khalili S.T.,Islamic Azad University at Karaj | Mohsenifar A.,Nanozino Co. | Mohsenifar A.,Nanosystems Research Team NRTeam | Beyki M.,Islamic Azad University at Tehran | And 6 more authors.
LWT - Food Science and Technology | Year: 2015

This study was set to investigate the encapsulation of the Thyme essential oils using chitosan and benzoic acid-made nanogel in order to enhance its antifungal properties and half-life. To achieve this, the self-assembled polymer of chitosan and benzoic acid nanogel (CS-BA) was synthesized, its size and shape were confirmed by spectrometric (FTIR) and microscopic methods (TEM and SEM) and was then used in encapsulating the essence. Under sealed condition, the minimum inhibitory concentration of the CS-BA encapsulated essential oils was recorded at 300mg/l while the free Thyme extract could only completely prevent the growth of Aspergillus flavus at an elevated concentration of 400 mg/l. Under non-sealed condition, higher concentration of encapsulated Thyme essential oils (500 mg/l) was required to cause complete fungi inhibition and free oils failed to lead to full inhibition even at concentrations as high as 1000 mg/l. Invivo analysis also revealed significant anti-fugal properties of the encapsulated oils at concentrations above 700 mg/l. Overall, due to the volatility and instability of free essential oils, CS-BA nanogel encapsulation was found to have significantly increased half-life and the anti-fungal properties of Thyme essential oils. © 2014. Source


Shahrashoob M.,Payame Noor University | Mohsenifar A.,Nanosystems Research Team NRTeam | Tabatabaei M.,Nanosystems Research Team NRTeam | Tabatabaei M.,Agricultural Biotechnology Research Institute of Iran | And 4 more authors.
Journal of Applied Spectroscopy | Year: 2016

A novel optics-based nanobiosensor for sensitive determination of the Helicobacter pylori genome using a gold nanoparticles (AuNPs)-labeled probe is reported. Two specific thiol-modified capture and signal probes were designed based on a single-stranded complementary DNA (cDNA) region of the urease gene. The capture probe was immobilized on AuNPs, which were previously immobilized on an APTES-activated glass, and the signal probe was conjugated to different AuNPs as well. The presence of the cDNA in the reaction mixture led to the hybridization of the AuNPs-labeled capture probe and the signal probe with the cDNA, and consequently the optical density of the reaction mixture (AuNPs) was reduced proportionally to the cDNA concentration. The limit of detection was measured at 0.5 nM. © 2016 Springer Science+Business Media New York. Source

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