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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14411/18
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Article Gold-Assembled Silica-Coated Cobalt Nanoparticles as Efficient Magnetic Separation Units and Surface-Enhanced Raman Scattering Substrate Lütfiye Sezen Yildirim1,, Murat Kaya2,∗,, Mürvet Volkan(Tubitak Scientific & Technological Research Council Turkey, 2019) Yıldırım, Lütfiye Sezen; Kaya, Murat; Volkan, MürvetMagnetic and optical bifunctional nanoparticles that combine easy separation, preconcentration, and efficientSERS capabilities have been fabricated with high sensitivity and reproducibility through a low-cost method. Thesegold nanoparticles attached on magnetic silica-coated cobalt nanospheres (Co@SiO2 /AuNPs) display the advantageof strong resonance absorption due to gaps at nanoscale between neighboring metal nanoparticles bringing large fieldenhancements, known as “hot spots”. The prepared particles can be controlled by using an external magnetic field,which makes them very promising candidates in biological applications and Raman spectroscopic analysis of dissolvedorganic species. The magnetic property of the prepared particles lowers the detection limits through preconcentrationwith solid-phase extraction in SERS analysis. The performance of the prepared nanostructures was evaluated as a SERSsubstrate using brilliant cresyl blue (BCB) and rhodamine 6G (R6G) as model compounds. The solid-phase affinityextraction of 4-mercapto benzoic acid (4-MBA) using bifunctional Co@SiO2 /AuNPs nanoparticles followed by magneticseparation and the measurement of the SERS signal on the same magnetic particles without elution were investigated.Approximately 50-fold increase in SERS intensity was achieved through solid-phase extraction of 8.3 × 10 −6 M 4-MBAin 10 min.Article Citation - WoS: 3Citation - Scopus: 4Identification of Bacterial Diversity of Bee Collected Pollen and Bee Bread Microbiota by Metagenomic Analysis(Aves, 2022) Arserim Ucar, Dilhun Keriman; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Yegin, Zeynep; Ozalp, Veli Cengiz; Sudagidan, Mert; Uçar, Dilhun Keriman Arserim; Ozalp, Cengiz; Arserim-uçar, Dılhun KerimanThis study investigated the bacterial diversities of bee-collected pollen and bee bread of Apis mellifera in Turkey. The bacterial community structure of 14 bee pollen from Bingol, Konya, and Hakkari and 11 bee bread samples from Bingol were studied using 16 S rRNA amplicon sequencing and metagenomic analysis. The dominant bacterial phylum in pollen and bee bread samples was Firmicutes, followed by Proteobacteria. In pollen and bee bread samples, Bacillaceae, Clostridiaceae, Enterococcaceae, and Enterobacteriaceae were identified as dominant bacterial families. At the genus level, Bacillus, Clostridium sensu stricto, and Enterococcus were dominant bacteria in both pollen and bee bread samples. The most abundant species was Clostridium perfringens in both pollen and bee bread samples. Escherichia vulneris, Enterococcus faecalis, Bacillus cereus, Enterococcus casseliflavus, and Cronobacter malonaticus were identified with high reads in pollen samples. In bee bread samples, E. faecalis, Clostridium bifermentans, and Pantoea calida were abundant bacterial species. Alpha diversity showed that pol-3 sample had the highest diversity. Beta-diversity plots separated the pollen samples into four main groups and bee bread samples into three main groups. Our results indicated that the culture-independent metagenomic analysis will be a valuable tool for determining the microbial diversity of bee products produced in Bingol-Turkey one of the important centers of apiculture.