Ayse Demirbas

Recep Tayyip Erdogan University · Faculty of Fisheries

In this study, silver@graphene oxide nanocomposites (Ag@GO NCs) derived from extracts of Antarctic lichens Usnea antarctica and Umbilicaria antarctica were synthesized and their antimicrobial activity against to fish pathogen bacteria were evaluated. According to the results of characterization test, spherical Ag NPs were well dispersed on the surf...

This study, it was aimed to examine the change in the antimicrobial effect of sea anemone Parazoanthus axinellae extract by forming its nanoflowers. A scanning electron microscope (SEM) and energy dispersive X‐ray spectroscopy (EDX) were expended to observe the morphologies of the Cu NFs that had been produced. Fourier transform infrared spectrosco...

In the context of the proposed work, two different amino acids (Glycine, Phenylalanine) have interacted with copper ions in a phosphate buffer (PBS) in place of enzymes. This interaction resulted in the nucleation of copper phosphate crystals and the formation of flower-shaped amino acid-copper hybrid nanostructures (AA-hNFs), which grew through se...

This work describes a unique and environmentally friendly approach for creating three-dimensional (3D) organic-inorganic flower shaped hybrid nanostructures called "nanoflower (NF)" by using Umbilicaria decussate (U. decussate) extract and copper ions (Cu2+). U. decussate species were collected from certain place in Antarctic and Turkey and extract...

Due to its distinct, atypical features and possible applications, three-dimensional (3D) hierarchical nanoflowers have sparked considerable interest. Copper (II) ions were employed as inorganic components in this study, whereas various extracts from Aspergillus terreus and their extracted main components were used as organic components. Extracts fr...

Herein, we used lichen extracts, for the first time, in formation of organic‐inorganic nanoflowers and we utilized them as novel nanobiocatalyst and antimicrobial agents. Two lichen species, Usnea Antarctica (U. Antarctica) and Usnea subfloridana (U. subfloridana) were collected from James Ross Island (Artarctica Peninsula, Antarctica) and from Ulu...

First time in this study, the antibacterial effects of Axinyssa digitata sponge extracts and Axinyssa digitata -based cupper hybrid nanoflowers (Cu hNFs) were evaluated. Herein, hybrid nanoflowers (Cu hNFs) were produced by combining Axinyssa digitata sponge extract with Cu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http...

Herein, we report the synthesis of taurine incorporated (sulfur containing organic molecule derived from methionine and cysteine) hybrid nanoflowers (thNFs) with an intrinsic peroxidase-mimic and antimicrobial activities in the presence of H2O2. Formation of thNFs using non-enzyme molecules was for the first time and systematically studied as a fun...

The essential goals of this present study are to elucidate the formation mechanism of ellagic acid rich-blackberry, BBE, (Rubus fruticosus L.) and raspberry, RBE, (Rubus idaeus L.) extracts directed silver nanoparticles and to investigate thier antimicrobial properties towards model dental pathogens E. faecalis and C. albicans compared to BBE, RBE,...

The aim of the current work is to examine the concentrations of nine heavy metals such as chromium, nickel, copper, cadmium, zinc, cobalt, iron, lead, and metal (aluminium) in two body parts (carapace and walking legs) of Liocarcinus depurator from different stations (İlyas bey, Cide koyu, Anadolu feneri, igneada) in the western Black Sea coast of...

In this work, we synthesized blood orange peel extract-copper (II) (Cu2+) ions nanoflower (NFs) and blood orange juice extract-copper (II) (Cu2+) ions nanoflower examine their antimicrobial properties on the fish pathogen (Yersinia ruckeri). The main compounds of the blood orange peel extract and the blood orange juice extract were organic componen...

Bu çalışmada, altın çilek meyve ekstresi-bakır (II) (Cu2+) iyonları nanoflower (NFs) ve altın çilek kabuk ekstresi-bakır (II) (Cu2+) iyonları nanoflower (NFs) sentezlendi. Ve bu sentezlerin gıda kaynaklı bakteriyel patojenler (Staphylococcus aureus, Escherichia coli, Aeromonas spp. ve Basillus cereus) üzerine antimikrobiyal etkisi ayrıca sentezlene...

The members of the genus Sideritis have a wide variety of phytochemicals and thus the genus are gaining interest to fabricate nanoparticles (via green synthesis) as sources reducing or stabilizer agents. In the present study, silver nanoparticles (AgNPs) were synthesized by an easy and eco-friendly method using aqueous extracts of three Sideritis s...

Packaged fresh food is one of the factors that trigger the shelf life negatively; It is at the forefront that the liquid percolated by food accumulates inside of the package, accelerating chemical and microbial spoilage and finalized with reducing food quality. In order to prevent the accumulation of liquid in the package, the absorbent pads dispos...

Materials in nano size called “nanomaterials” convey novel and enhanced properties based upon their size, shape, morphology, and component and have been intensively employed in a variety of scientific and industrial fields. Specifically, nanomaterials have been exposed to humans, plants, and animals, so toxicity of nanomaterials is a crucial issue...

Enzymes are natural and highly active biological molecules that increase the speed of catalytic reactions. They are used in various biotechnological and industrial areas due to their characteristics such as activity at diverse pHs and temperatures, easy production, high substrate specificity and selectivity, green chemistry, reusability, biodegrada...

In this work, plant extract-metal ions hybrid nanoflowers (HNFs) were synthesized and their catalytic and antimicrobial properties were examined. While the sweet and sour lemon peel extract (acquired in boil water) and its primary elements were engaged as organic elements in the creation of NFs, copper (II) ions (Cu 2+) were the inorganic element....

This study was performed to evaluate effects of red cabbage extract as a preservative against lipid oxidation for quality and shelf life of minced Tilapia (Nile perch) during refrigerated storage at 4  1°C. Untreated and treated samples were examined from day 0 to 10 during refrigerated storage using thiobarbituric acid reactive substances (TBARS)...

Herein, we have reported the synthesis, characterization and catalytic activity of highly stable gold nanoparticles (Au NPs) using red cabbage extract (RCE) under UV irradiation. The anthocyanin groups predominantly existing in RCE play an essential role for biosynthesis of stable Au NPs. The reasons for using anthocyanins: 1) they act as chelating...

We report synthesis of monodispersed, stable, and colloidal gold nanoparticles (Au NPs) using anthocyanin-riched red raspberry (Rubus idaeus), strawberry (Fragaria ananassa), and blackberry (Rubus fruticosus) extracts as functions of concentration of HAuCl4·3H2O and berries extract, reaction time, and reaction pH values (pHs) and demonstrate their...

Silver nanoparticles(Ag NP) have been used for over a century for many purposes including as germicides. Unique physical, chemical and biological properties of Ag NPs make them suitable for a wide range of applications in different industries and biomedical fields. Green nanobiotechnology with synthesis of NPs using biomolecules(protein, enzyme, DN...

The discovery of functional organic–inorganic hybrid nanoflowers (FNFs) consisting of proteins/enzymes as the organic components and Cu(II) ion as the inorganic component has made an enormous impact on enzyme immobilization studies. The FNFs synthesized by an encouraging and novel approach not only showed high stabilities but also much enhanced cat...

A recent breakthrough in preparation of immobilized enzyme based biocatalysts achieving highly enhanced enzymatic activities and stabilities has become a great alternative to conventional immobilization techniques. The functional hybrid nanobiocatalysts (FHNs) fabricated in this immobilization composed of organic components (amino acid, peptide, pr...

Herein we report anthocyanins-rich berries (Rubus fruticosus L. (blackberry); Fragaria vesca L. (strawberry) and Rubus idaeus L. (raspberry)) extracts directed silver nanoparticles (Ag NPs) and systematically investigate their antioxidant and antimicrobial activities. We also fabricated Ag NPs using standards molecules, gallic acid and catechin, as...

Flavonoids are important value added products for dye sensitized solar cells biosensors, functional foods, medicinal supplements, nanomaterial synthesis, and other applications. Brassica oleracea contains high levels of anthocyanins in leaf sap vacuoles, and there are many viable extraction techniques that vary in terms of simplicity, environmental...

Various concentrations of Matricaria chamomilla (M. chamomilla) flower extract was used for biosynthesis of Ag NPs with different sizes, 70 ± 5 (Ag NP-1), 52 ± 5 (Ag NP-1) and 37 ± 4 nm (Ag NP-3), and size-specific antimicrobial activity of them was evaluated towards Gram + Staphylococcus aureus (S. aureus), Gram − Escherichia coli (E. coli) bacter...

In this study, we report, for the first time, the combination of green and hydrothermal synthesis approaches for biosynthesis of red cabbage extract directed spherical Ag NPs with high yield and monodispersity. The Ag NPs have a very narrow size distribution and enhanced inhibitory properties against Staphylococcus aureus (Gram +), Escherichia coli...

Oxidation of polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fish causes loss of product quality. Oxidative rancidity causes loss of nutritional value and undesirable color changes. Therefore, powerful antioxidant extracts may provide a relatively low cost and natural means to reduce oxidation, resu...

Plant extracts contain sources of antimicrobial and antioxidant compounds that have been used as a reducing and stabilizing agents for biosynthesis of nanoparticles (NPs). Some studies suggest that plant extracts incorporating directed NPs, such as Ag, enhanced antioxidant activity, this study suggests the opposite. Red cabbage extract with silver...