Recent Article Published: An investigation into the role of macromolecules of different polarity as passivating agent on the physical, chemical and structural properties of fluorescent carbon nanodots

In this study, comparative evaluation of fluorescent carbon nanodots (C-Dots) prepared using carob molasses was reported by screening various biocompatible macromolecules as passivating agent (PA). Incorporation of PAs with different molecular weight, polarity, and chemical structure was examined, and compared with the polyethylene glycol (PEG, Mn = 10 kN) passivated and pristine C-Dots. Not only the fluorescence properties but also many other features including size, crystal structure, colloidal conductivity, resistance to photobleaching, quantum yield, and UV-modulated surface interaction of them with the reactive oxygen species (ROS) as well as ROS production were investigated. Photoluminescence (PL) capacity of C-Dots was found to be associated with the number of surface alkyl groups and polymeric hydrogen bonding present on the C-Dot surface (increased number is associated with decreased PL) while the surface conductivity of C-Dots in water was proportional to the PL intensity. More importantly, C-Dots with relatively poorer fluorescent were investigated in various organic solvents (hexane, methanol, acetone, ethanol, dimethylformamide (DMF), and DMSO). As happens with the fluorescent dyes, their PL intensities were significantly enhanced (even for pristine C-Dots) depending on the solvent characteristics. All of the C-Dots synthesized were further evaluated by means of UV-induced generation of ROS and inhibition of ROS by using H2O2 as a model. In contrary to other carbonaceous nanomaterials, they did not show any ROS generation, on the contrary, they showed ROS scavenging activity that can be modulated by UV-irradiation (λexc = 365 nm). PEG and alginate passivated C-Dots inhibited H2O2 activity at LC50 values below 10 mg/mL.

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Cite this article as: Alas, M.O. & Genc, R. J Nanopart Res (2017) 19: 185. doi:10.1007/s11051-017-3863-1

Recent Article Published: Green Synthesis of Fluorescent Carbon Nanoparticles and Investigation of the Effect of Passivating Agent Molecular Weight on Nanoparticle Properties

In this research article , synthesis of fluorescent carbon nanoparticles from a natural carbon source, carob molasses, was investigated. To this end, thermal synthesis methodology as a green synthesis method with the easşekil2iness to carry out and being economical was followed and polyethylene glycol of different molecular weight (PEG Mn: 300~20000) was used as surface passivating agent.  Synthesized fluorescent carbon nanoparticles (FCNPs) were then characterized by field emission scanning electron microscope (FE-SEM), transmission electron microsocope (TEM), X-Ray Diffraction Analysis (XRD), UV spectrophotometer, fluorescence spectrophotometer, dynamic light scattering (DLS) methods. Results showed that surface properties of nanoparticles and fluorescent properties as a result were found to be determined by the molecular weight of the passivation agent. Moreover, hydrodynamic size of nanoparticles with core diameter measured as 10-15 nm was also found to be increased with increased polymer Mn.

MÖ Alas, R Genc  (2016) Sinop Üniversitesi Fen Bilimleri Dergisi 1 (2), 123-129

Recent Book Chapter Published: Nanoparticle based sensor platforms for facile detection of food contaminants (Chapter 10) in Nanobiosensors (Academic Press, Elseiver)

A Grumezescu

Academic Press

9780128043011

926

     As a comprehensive resource on nanotechnology in the agri-food industry, this book presents the principles and safety applications of biosensor nanotechnology.

 

Recent Article Published: Photoactive nanocomplex formed from chlorophyll assembly on TMA-coated iron oxide nanoparticles

Sibel Barbaros, Zeynep Meray, Tugba Tecim, Rukan Genc*

Journal of Nanoparticle Research, (2016), 18(185),  1-13, DOI:10.1007/s11051-016-3496-9

tableofcontIn this study, hierarchical self-assembly of photocatalytic nanodisks through non-covalent interactions between spinach-extracted chlorophyll molecules and trimethylammonium hydroxide-coated magnetic iron oxide nanoparticles was discussed. Combination of chlorophyll molecules with iron oxide nanoparticles generated an alteration in light absorption at both visible and near-IR region with accompanying enhancement in fluorescence emission. Further, photocatalytic role of resulting molecular assembly was studied by means of the photoinduced degradation of methylene blue dye under UV light and direct sun irradiation at neutral pH. In order to enhance the long-term stability of the hybrid nanocatalyst, commercially available cellulose membrane was used as a support and magnetic recovery and reusability was achieved where the nanocatalyst retained more than 90 % of its efficiency even after four cycles. This simple strategy could initiate the development of new materials for wastewater treatment including membrane-based technologies. On the other hand, their sunlight-induced photocatalytic activity could easily be conducted to dye-synthesized solar cells or their enhanced photoluminescence can provide a strong basis for future bioimaging tools.

 

Recent article published: Magnetic nanoparticle embedded stimuli responsive hydrogels as anti-inflammatory drug-carriers

Sibel Barbaros, Rukan Genç*

Dokuz Eylul Universitesi Muhendislik Dergisi, 18(1) pp31-3., 2016, DOI:10.21205/deufmd.20165217543.

In this study, magnetic alginate beads were successfully synthesized by integrating superparamagnetic iron oxide nanoparticles (Fe3O4) in sodium alginate microbeads during the synthesis. The as-obtained dried samples were analyzed by means of their water detention capacity and drug encapsulation efficiency. Further, an anti-inflammatory drug (Cefazolin), mostly used for the treatment of joint inflammations after surgery, was used as a model drug in order to evaluate the stimuli-responsive properties of macrocomposites under magnetic field for the development of on-site drug delivery system. To do so, their drug release kinetics at changing environmental conditions, such as pH, temperature, and magnetic field were investigated and compared with bare alginate beads.


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Recent Article Published: Shape directed biomineralization of gold nanoparticles using self-assembled lipid structures

Rukan Genc*, Gael Clergeaud, Mayreli Ortiz and Ciara O’Sullivan*

Biomater. Sci., 2014, Advance Article DOI: 10.1039/C4BM00025K, Paper 

Scheme1

As one of the building blocks of the cell membrane, lipids and their interaction with neighboring lipids and other molecules, as well as their ability to form different kinds of structures, have garnered immense interest. By exploiting the effective shape and thermal-phase behavior of lipids, we have prepared lipid superstructures such as twisted ribbons and rectangular and hexagonal shaped lipidic nanostructures using the curvature tuned preparation method. These lipidic superstructures were then used as nanoreactor templates for the inorganic synthesis of diversely shaped and sized gold nanostructures exploring different administration routes of reducing agents, citrate, and tetrachloroauric acid, which as a result formed different organizations of gold nanoparticles aligned and guided by the template structure. Tailor-designed metallic nanostructures can be obtained through a careful selection of lipids and conditions for lipid superstructure preparation and their consequent use as template nanoreactors. The diversely sized and shaped gold nanostructures obtained have great potential for catalysis and plasmonics.

Book Chapter Published in “Biosensors: Recent advances and mathematical challenges”

Book Chapter Published in “Biosensors: Recent advances and mathematical challenges”

About the Book: Many researchers and research groups around the globe are dealing with interdisciplinary problems and multidisciplinary groups; but especially those that deal everyday with biosensors have the feeling of not having enough personnel with the sufficient background to cover all topics. With this feeling in our minds, we decided to invite wonderful researchers from different parts to design this book, not as a conventional biosensor’s book, but as an interesting journey in the complex world of biosensors. A close look to some recent and key advances on the topic, but at the same time tips through novel mathematical modelling to improve our work, and last but not least, tricks to fool those undesired electrical  disturbances that commonly messes our daily work can be found in these pages.

Feel free to navigate the book through its chapters, once in your hands you will feel eager to learn more about biosensors. It has been an experience to put all this together; but now, with the book ready, we can say that this trip has being a wonderful adventure. That is why want to thank all the authors for their great contributions, the Editorial and Irene for their constant input, and to you, the reader, for being part of this book.

About the Chapter (1)-Use of functonal metalic nanostructures in biosensors by Rükan Genç. 

The number of diferent type of nanostructures is increasing and wide range of nanoscale materials of diferent sizes, shapes and compositons are now available . From those, mainly, nanomaterials can be divided into three main classes depending on the material they are made up of: i) inorganic nanopartcles where the core material is an inorganic element or mixture (e.g; gold, silver, TiO2, ZnO, CdS and so on), ii) organic sof nanomaterials which are formed of organic materials including lipids, peptdes, genetc material, and finally, iii) nanocomposites which are based on both organic and inorganic materials, for example, magnetosomes, metal coated carbon nanotubes  and peptde amphiphiles. However, this chapter will only cover the state of the art associated to the advantages ofered by diferent types of inorganic nanomaterials and their composites. Collecton of literature on challenges and drawbacks, and real world applicatons of these kinds of nanomaterials in biosensor development, including current status and future prospects will also be served to the readers’ interest.