Azade Attar

Yildiz Technical University · Department of Bioengineering

Copper oxide nanoparticles (CuONPs) synthesized using Knautia arvensis flower extract in an environmentally friendly and one-step procedure were characterized by UV–vis, FT-IR, SEM and DLS. The in vitro antibacterial and antifungal activities of CuONPs were determined using E. coli, S. aureus and A. niger. In silico antibacterial and antifungal eva...

Copper oxide nanoparticles (CuONPs) are used in many fields from electronics to medicine due to their multifunctionality, and therefore, their production with environmentally friendly methods is a current issue. In this study, biofabricated CuONPs were obtained by using the leaf extract of Acer palmatum plant originating from the Far East to enligh...

Improvement of the thermal properties of coolants used in automobile radiators increases the cooling performance of the engine. Metallic nanoparticle additives generally improve the thermal properties of the coolant. In this study, the heat transfer characteristics of a nanofluid prepared with bimetallic additives (CuO–ZnO) for automotive radiators...

The demand for metal nanoparticles is increasing with the widening application areas while causing environmental impact including pollution, toxic byproduct generation and depletion of natural resources. Incorporating natural materials in nanoparticle synthesis can contribute toward environmental sustainability. This paper is concerned with the bio...

In this study, copper oxide nanoparticles (CuONPs) were synthesized by sol-gel method and characterized by SEM. The stability and the heat transfer performance of the synthesized nanoparticles was evaluated by adding to the radiator coolant at different concentrations. The average diameter of the CuONPs produced was 80 nm and they were in a spheric...

In this study, bioinspired fabrication of copper oxide nanoparticles (CuONPs) which are widely researched in nanotechnology field with Cotoneaster extract was performed. Cotoneaster plant extract was chosen as a good antioxidant and antibacterial agent in terms of the amount of phenolic and flavonoid compounds it contains. The obtained CuONPs were...

Tea is a worldwide consumed herbal beverage and it was aimed in this study to reveal the major fractions of green and black tea in order to enlighten the in vitro inhibition potency on the well‐known drug metabolizing enzyme CYP2D6 activity. Methylxanthine fractions were extracted from green and black tea and a yield of 0.265 g (1.06%) for 25 g of...

Current environmental concerns on nitrogen oxides (NOx) and particulate matter (PM) emissions caused by diesel engines have led researchers to be interested in investigating vehicles with alternative power sources. Because of this reason, vehicle models with SI engine were adopted in the conducted study. Firstly, as an initial step, 1-D SI engine m...

Copper oxide nanoparticles (CuONPs) were phytosynthesized via Laurus nobilis leaf extract which was used as reducing and capping agent. UV‐vis spectroscopy was applied and the spectrum of CuONPs gave a peak around 300 and 325 nm. An intense Fourier transform infrared spectroscopy (FT‐IR) between 4000–500 cm−1 wavelengths exhibited exterior function...

Horseradish peroxidase (HRP) characteristics were improved by two techniques, Na-alginate entrapment and glutaraldehyde crosslinking prior to alginate entrapment, in order to enhance the stability, functionality and removal of dyes in waste water. Free, entrapped and crosslinked-entrapped enzymes were compared by activity assays indicated the optim...

In this study, the different mole ratios of glucose oxidase/chitosan/dextran–aldehyde and glucose oxidase/chitosan/dextran–sulfate complexes were synthesized. The modification of glucose oxidase by non-covalent complexation with dextran and chitosan in different molar ratios was studied in order to increase the enzyme activity. The enzyme/polymer c...

Non-covalent complexes of urease/polyethylene glycol (PEG)-aldehyde were synthesized using regular molar ratios of urease and PEG-aldehyde at room temperature. The physical properties of the non-covalent complexes were analyzed in order to investigate the impact of coupling ratio, temperature, pH, storage stability, and thermal stability. Urease ac...

This study reports a novel precursor for the ecofriendly and low cost biosynthesis of economically important titanium dioxide nanoparticles (TiO 2 NPs) using Salvia officinalis. TiO(OH) 2 was used for the biosynthesis of nanoparticles with the aqueous solution of Salvia officinalis leaf extract. The evaluation of the biosynthesis of TiO 2 NPs were...

Palladium, the building block of white gold, has been found to exhibit extraordinary properties in nanotechnological products produced in recent years. The most prominent feature of palladium is adsorbing and storing high levels of hydrogen. Therefore, the demand for palladium in the world increased excessively in the 2000s. In the present study, p...

Zinc oxide and gold nanoparticles (ZnONPs and AuNPs) are biomimetically synthesized using Echinacea angustifolia flower extract and their structure and biological activities are reported. In this process, the dried flowers extracts reduced the zinc metal from the precursor Zinc nitrate hexahydrate [Zn(NO3)2.4H2O] and stabilized within 6 h. Gold nan...

The benefits of nitrogen-fixing and potassium-solubilizing microorganisms in plant growth were investigated by using micro-sized ion-selective sensors developed in our laboratory. Azorhizophilus paspali (ATCC 23367) having nitrogen-fixing capability and Paenibacillus mucilaginosus (DSM 24461) having potassium-solubilizing capability were used in me...

A novel all solid-state contact PVC-membrane beryllium-selective electrode based on 4-hydroxybenzo-15-crown-5 ether as an ionophore is described. The best performance was obtained with a membrane composition of 4% ionophore, 67% dioctyl sebacate (DOS), 28% poly(vinyl chloride) (PVC), and 1% potassium tetrakis (p-chloro)phenylborate (KTClPB) (w/w)....

The investigation aims the synthesis of copper oxide nanoparticles (CuO NPs) using Ocimum basilicum plant extract at room temperature. This method is completely a green method, free from toxic and harmful solvent. The CuO NPs were sytnhesized by mixing copper sulphate dehydrate (CuSO4.5H2O) and aqueous Ocimum basilicum leaf extract. The biosynthesi...

The ability of Archaea to adapt their membrane lipid compositions to extreme environments has brought in archaeosomes into consideration for the development of drug delivery systems overcoming the physical, biological blockades that the body exhibits against drug therapies. In this study, we prepared unilamellar archaeosomes, from the polar lipid f...

Gene therapy is used for developing strategies for the treatment of genetic diseases and it is a promising technique for people with incurable diseases. A successful gene therapy includes the transfection of plasmids with related transgenes into the target cells. The transfer of the DNA molecule to target cell is the main problem of the gene therap...

In this study, a micro-sized lactate sensitive biosensor based on polyvinylchloride, quinhydrone and graphite composite pH sensing platform was developed. Lactate oxidase was immobilized on the composite layer as the biorecognition element. Transformation reaction of lactate to pyruvate and hydrogen peroxide was the basis of this biosensor system....

A trace quantification liquid chromatographic-potentiometric method for the determination of amines in cheese serum is described. An all solid-state contact polyvinyl chloride membrane amine-selective electrode was prepared and used as a detector in a low-dead volume flow through detection cell. Potentiometric performance characteristics of the pro...

A strain of Haloarcula hispanica isolated from Tuzkoy salt mine, Turkey exhibited extracellular lipolytic activity. Important parameters such as carbon sources and salt concentration for lipase production were investigated. Optimal conditions for the enzyme production from Haloarcula hispanica 2TK2 were determined. It was observed that the lipolyti...

A microliter dead-volume flow-through cell as a potentiometric detector is described in this article for sensitive, selective and simultaneous detection of common monovalent anions and cations in single column ion chromatography for the first time. The detection cell consisted of less selective anion- and cation-selective composite membrane electro...

A new type of Fe2O3 based silicone composite pH electrode was investigated for using as a potentiometric pH sensor. Potentiometric performance characteristics of the prepared electrode were tested in steady-state conditions by using a computer-controlled potentiometric system. The electrode was constructed with a mixture of sulfated iron (III) oxid...

Halophilic archaea offer a potential source for production of polyhydroxyalkanoates (PHAs). Hence, the experiments were carried out with five extremely halophilic archaeal isolates to determine the highest PHA-producing strain. PHA production of each isolates was separately examined in cheap carbon sources such as corn starch, sucrose, whey, apple,...

This paper describes the formulation of archaeosomes and the evaluation of their abilities to facilitate in vitro DNA delivery. Lipids of the H.hispanica 2TK2 strain were used in archaeosome formation, which is formulated by mixing H.hispanica 2TK2 lipids with plasmid DNA encoding green fluorescent protein (GFP) or β-galactosidase (β-gal). Archaeos...

Ultrasonic irradiation is considered to be an effective way to increase the mass transfer between the immiscible liquid-liquid phases in a heterogeneous system leading to faster transesterification and higher yield, and saving excess methanol and catalyst. In this study, the transesterification of hazelnut oil with methanol and ethanol was performed...

A novel potentiometric sensor based on ionophore (Cd(NH2CH2CH2OCH2CH2OCH2CH2NH2)Ag3(CN)5) for the determination of β -N-oxalyl-l- α , β -diaminopropionic acid (ODAP) is developed. The ODAP-selective membrane sensor demonstrates high sensitivity and short response time. The detection limit of the ODAP-selective membrane sensor is about 2 × 10(-6) mo...

A novel potentiometric sensor based on ionophore (Cd(NH 2 CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 NH 2)Ag 3 (CN) 5) for the determination of-N-oxalyl-l- ,-diaminopropionic acid (ODAP) is developed. The ODAP-selective membrane sensor demonstrates high sensitivity and short response time. The detection limit of the ODAP-selective membrane sensor is about 2 ×...

Halophilic archaea adapted to life at salt concentrations at or nearly saturation and haloarchaeal proteins have specific properties for adapting to highly salty environments, so that their proteins maintain stability and functionality in extreme habitats. Extracellular enzymes of halophiles are always exposed to high salt must have unique amino ac...

Objective: The effect of different concentrations of antioxidants (ascorbic acid, emoxipin, tocopherol acetate and ionol) on antibiotic sensitivity of bacteria was studied. Method: Bacteria belong to different respiration types: Pseudomonas aeruginosa as aerobe and Escherichia coli as facultative anaerobe were used. Antibiotic sensitivity of microo...