Publications by authors named "Anara Molkenova"

4 Publications

  • Page 1 of 1

Cetyltrimethylammonium Bromide (CTAB)-Loaded SiO-Ag Mesoporous Nanocomposite as an Efficient Antibacterial Agent.

Nanomaterials (Basel) 2021 Feb 13;11(2). Epub 2021 Feb 13.

Department of Chemistry, Nazarbayev University, Nur-Sultan 010000, Kazakhstan.

To date, Ag-based nanomaterials have demonstrated a high potential to overcome antibiotic resistance issues. However, bare Ag nanomaterials are prone to agglomeration in the biological environment, which results in a loss of antibacterial activity over time. Furthermore, it is still challenging to collect small-sized Ag nanomaterials right after the synthesis process. In this study, spherical-shaped Ag nanoparticles (NPs) (~6-10 nm) were attached on the surface of cetyltrimethylammonium bromide (CTAB)-loaded mesoporous silica nanoparticles (MSNs) (~100-110 nm). Antibacterial activity tests suggested that the obtained nanocomposite can be used as a highly efficient antibacterial agent against both Gram-negative and Gram-positive bacterial strains. The minimum inhibitory concentration (MIC) recalculated to pure Ag weight in nanocomposite was found to be ~1.84 µg/mL (for ) and ~0.92 µg/mL (for )-significantly smaller compared to values reported to date. The improved antibacterial activity of the prepared nanocomposite can be attributed to the even distribution of non-aggregated Ag NPs per volume unit and the presence of CTAB in the nanocomposite pores.
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http://dx.doi.org/10.3390/nano11020477DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7917824PMC
February 2021

Solution-Based Deposition of Transparent Eu-Doped Titanium Oxide Thin Films for Potential Security Labeling and UV Screening.

Nanomaterials (Basel) 2020 Jun 8;10(6). Epub 2020 Jun 8.

Department of Chemistry, Nazarbayev University, Nur-Sultan 010000, Kazakhstan.

Transparent titanium oxide thin films attract enormous attention from the scientific community because of their prominent properties, such as low-cost, chemical stability, and optical transparency in the visible region. In this study, we developed an easy and scalable solution-based process for the deposition of transparent TiOx thin films on glass substrates. We showed that the proposed method is also suitable for the fabrication of metal-doped TiOx thin films. As proof-of-the-concept, europium Eu(III) ions were introduced into TiOx film. A photoluminescence (PL) study revealed that Eu-doped TiOx thin films showed strong red luminescence associated with D→F relaxation transitions in Eu (III). We found that prepared TiOx thin films significantly reduce the transmittance of destructive UV radiation; a feature that can be useful for the protection of photovoltaic devices. In addition, transparent and luminescent TiOx thin films can be utilized for potential security labeling.
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http://dx.doi.org/10.3390/nano10061132DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7353274PMC
June 2020

Carbon Dots Doped with Dysprosium: A Bimodal Nanoprobe for MRI and Fluorescence Imaging.

J Funct Biomater 2018 May 18;9(2). Epub 2018 May 18.

Department of Chemistry, School of Science and Technology, Nazarbayev University, Astana 010000, Kazakhstan.

In recent years, functional nanoprobes with multiple imaging modalities have become an emerging field of biomedical research. In this preliminary study, we utilized a facile hydrothermal method for the preparation of magneto-fluorescent bimodal carbon dots doped with dysprosium (Dy-CDs). The prepared Dy-CDs have shown a good colloidal stability in a water solution and strong blue⁻green fluorescence, with a maximum at 452 nm. In addition, the excellent transverse relaxivity of the prepared Dy-CDs (r₂ = 7.42 ± 0.07 mMs) makes them also suitable for T₂-weighted magnetic resonance imaging (MRI). Thus, synthesized Dy-CDs could be potentially utilized for both MRI and fluorescence imaging of living cells.
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http://dx.doi.org/10.3390/jfb9020035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6023474PMC
May 2018

Single-step co-deposition of nanostructured tungsten oxide supported gold nanoparticles using a gold-phosphine cluster complex as the gold precursor.

Sci Technol Adv Mater 2014 Dec 9;15(6):065004. Epub 2014 Dec 9.

Department of Chemistry, University College London, 20 Gordon Street, WC1H 0AJ London, UK.

The use of a molecular gold organometallic cluster in chemical vapour deposition is reported, and it is utilized, together with a tungsten oxide precursor, for the single-step co-deposition of (nanostructured) tungsten oxide supported gold nanoparticles (NPs). The deposited gold-NP and tungsten oxide supported gold-NP are highly active catalysts for benzyl alcohol oxidation; both show higher activity than SiO supported gold-NP synthesized via a solution-phase method, and tungsten oxide supported gold-NP show excellent selectivity for conversion to benzaldehyde.
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http://dx.doi.org/10.1088/1468-6996/15/6/065004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5090393PMC
December 2014