MIIT, Universiti Kuala Lumpur (UniKL), Malaysia
Ternary Flip-Flop based on Carbon Nanotube Field Effect Transistor
Dr. Soheli Farhana has completed her PhD in engineering from International Islamic University Malaysia and postdoctoral fellowship from International Islamic University Malaysia, Malaysia. She was the visiting researcher at ONE Lab, MIT, MA, USA. She has published several articles in reputed journals and has been serving as an editorial board member of reputed journals. Dr. Farhana is also serving as the committee member in several conferences. She is the reviewer of IEEE Transaction on Power Electronics and some relevant journal in Springer publication. Currently, Dr. Farhana is working as a visiting research professor at MIIT, UniKL, Kuala Lumpur, Malaysia. Her current research interests include Nanostructure materials, Nano-Electronics, Electrochemical properties of nanostructure and Nano Biosensor.
The scaling of current CMOS technology to nanoscale range leads to various critical challenges and reliability issues which will considerably reduce the potential of CMOS technology for high performance applications in near future. To handle these issues, such as electron tunneling through short channels and thin insulator films, variations in device structure and doping, increased leakage currents and high power dissipation towards new alternatives to replace bulk CMOS technology. Carbon nano tube field effect transistor (CNTFET) could be one promising and superior alternative, due to its resemblance with MOSFET in terms of intrinsic attributes and also due to its various superior characteristic. In CNTFET, the carrier velocity is almost double due to high mobility on account of ballistic transport operation with 1-D band structure than that of MOSFET.
This work shows a potential design of ternary circuits based on carbon nanotube transistors (CNTFETs) technology. Ternary logic is a promising alternative to the design of binary logic circuits; so it is possible to obtain simplicity and energy efficiency in the digital circuits design, namely, interconnections and chip area. Two types of ternary synchronous and asynchronous Flip-Flop is designed based on CNTFETs, which can be extended to the desired bits using the proposed Flip-Flop. Simulation results using SPICE CNTFET model demonstrate that the proposed ternary circuits consume significantly lower power and delay are 0.26µW and 177.7pS. Therefore, the reported results show that the presented CNTFET based ternary Flip-Flop design achieved great improvement in term of speed and power. Flip-Flip is used extensively as basic storage element in all kinds of digital systems.
Michigan State University, USA
Synergistic effect of post-deformation annealing on the micro-mechanical behavior of Zn-Mg hybrids processed by High-Pressure Torsion
Boehlert’s research interests include materials engineering; materials sciences; metallurgy; electron backscatter diffraction; intermetallics electron microscopy; metal matrix composites; titanium alloys and composites; mechanical behavior. His research group is concentrating on understanding the deformation behavior of hexagonal close packed metals, in particular, titanium zinc, and magnesium alloys, for a range of applications including the biomedical industry.
Heterostructured metals have attracted increasing interest because of their unique capability to overcome the strength-ductility trade off typically observed in engineering materials. Here, a new strategy for synthesizing heterostructured Zn-Mg hybrids is proposed via high-pressure torsion (HPT) followed by post-deformation annealing (PDA). Experimental results indicate a transition from a relatively homogenous nanograined structure after HPT, to a heterogeneous microstructure consisting of a bimodal grain size distribution with Mg2Zn11 and MgZn2intermetallic nanoprecipitates upon subsequent PDA. This led to a simultaneous increase in hardness and strain rate sensitivity. Close inspection of the strain hardening capability revealed that Zn-Mg HPT-processed hybrids followed a three regime behavior during plastic deformation. This mechanical response is suggested due to the activation of multiple strengthening mechanisms, including grain refinement, in-situ precipitation, and back-stress strengthening associated to geometrically necessary dislocations. Overall, the observed correlation suggests that the thermo mechanical processing can be tailored to obtain the desired hardening response across a HPT sample. This knowledge is expected to be transferable to other metal hybrid systems, thereby providing a means to design microstructures suitable for task-specific applications. Some of the targeted applications for this nanotechnology are biodegradable stents and implants.
Daura Refinery, Iraq
Supercritical Fluids as Reaction Media for Scalable Production of Carbon Nanomaterials
We have demonstrated scalable and selective synthesis of carbon nanotubes (CNTs), carbon nanofibers (CNFs), and onion-like carbons (OLCs) in a batch reactor using supercritical fluids (SCFs) as reaction media. The process utilizes toluene and alcohols (ethanol, propanol, and butanol) as carbon precursors in combination with ferrocene. Growth with supercritical toluene at 600 °C in the absence of water yields large diameter CNTs while introduction of 92.5 mmol/L of water enhances product yield by 50%, promoting formation of smaller diameter CNTs and decorating the exterior surface of CNTs with Fe nanoparticles. At 400 and 500 °C, in the absence of water, supercritical toluene produces mainly OLCs and CNFs, respectively. For alcohols, a gradual evolution of the morphology of nanocarbons forms from mainly OLCs to tube-like structures as the ratio of C/O atoms increases, possibly due to a decrease in the tendency of graphitic sheets to minimize their energies by curling into onion-like structures as chain length increases. This study provides a framework for utilizing SCF reaction media in a batch reactor to achieve scalable and selective growth of different nanocarbons and nanocarbon–metal nanocomposites
University of South Africa, South Africa
Synthesis, Functionalization, and characterization of Mesoporous silica nanoparticles for targeted Curcumin Delivery to Cancer Cells
In the fight against cancer, development of multifunctional drug carriers that can encapsulate, transport, and specifically release the drugs to cancer cells in an active and stimuli-responsive way is very important. In this study, mesoporous silica nanoparticles were successfully synthesized, functionalized with alginate and chitosan and bonded with folic acid. Curcumin loading, in-vitro drug release in phosphate buffered saline and acetate buffers, in vitro cytotoxicity assay, intracellular uptake and drug internalization by living cells were investigated. The as synthesized MSN particles were highly monodisperse with a hydrodynamic diameter of 639.9 nm. Layer-by-layer coating of MSN by polyelectrolytes and conjugation of folic acid were confirmed by TGA and the zeta potentials. High drug encapsulation efficiency and loading capacity of 53% and 2.3% were achieved at pH 5.5. In-vitro drug release confirmed absence of curcumin release at blood pH of 7.4 while an initial burst release was observed at acidic pH followed by a sustained curcumin release over 36 hours. MTT assay showed the biocompatibility of the drug carrier while confocal laser scanning microscopy confirmed the hyper uptake and internalization of the multifunctional drug carrier. Exposure of free curcumin, drug-loaded carrier with and without folic acid, to the surface of HeLa cells before and after folic acid blocking, showed the efficient folic acid receptor assisted drug internalization by the tumour cells. The investigation offered a route to fabrication of biocompatible, pH-responsive, tumour-specific drug carriers with sustained drug delivery. Further investigations of the in-vivo tumour efficacy of the developed carrier are underway.
Universidad de La Laguna, Spain
Surface Structure of Graphene Oxide: a tunable platform for removal of compounds of environmental interest
The chemically modified surface of graphene provides interesting opportunities for tuning adsorption properties. It is well-known the increasing concern about the vulnerability of water resources and water supplies worldwide, due to the presence pf organic and inorganic contaminants. Especially, with respect to so called, ermerging contaminants. In this study, materials derived from its surface chemical modification were characterized, tested for its capacity to remove and/or for adsorption of different kind of wastewater contaminants such as heavy metals, azodyes and pharmaceutical compounds (diclofenac, gemfibrozil, bezafibrate and clofibrate). The importance of temperature, pH, ionic strength, and ionic strength in uptaking of contaminats on the graphene oxide materials were studied. A discussion of possible interactions justifying the partitioning of analytes to the GO is included, considering not only the analytes’ physicochemical characteristics, aqueous environment, and chemical modification of the surface.
Universidade Federal de Santa Maria, Brazil
Poly (ε--caprolactone) nanoparticles with pH-responsive behavior improved the in vitro antitumor activity of methotrexate
Methotrexate (MTX, 2,4-diamino-N10-methyl-folic acid) is a cytotoxic drug with the competitive inhibition of dihydrofolate-reductase as pharmacological target. As this drug inhibits a key cellular function, its cytotoxic activity is not specific towards neoplastic cells and, consequently, the therapy often causes severe side effects. In this context, the conjugation of the active molecule to a nanostructured delivery system is a promising approach to achieve a more efficient antitumor therapy. Moreover, on account of pH differences between cancerous (~pHe 6.6 e 5.4) and healthy (pH 7.4) tissues, the design of pH-sensitive systems at micro/nano scale can be used to improve tumor-targeted drug delivery. Therefore, the main objective of this research was to prepare nanoparticles (NPs) based on the polymer poly (ε-caprolactone) (PCL) and with the nonionic surfactant poloxamer 407 as formulation stabilizer, as a carrier for the antitumor drug methotrexate. In addition, the biological properties of the proposed nanocarriers were evaluated using different in vitro cell models. The conjugation of the lysine-based amphiphile, 77KL, to the NP matrix was the approach used to reach a formulation responsive to pH variations. The NPs showed mean hydrodynamic diameter and drug entrapment efficiency of 178.5 nm and 20.52%, respectively. Improved formulation stability was achieved after lyophilization. Drug nanoencapsulation was also able to protect MTX from photodegradation induced by UVA and UVC radiation. The hemolysis assay was applied to study the pH-sensitive membrane-lytic activity and hemocompatibility of the NPs. The PCL-NPs appeared to be hemocompatibles and, owing to its pH-sensitivity, showed membrane-lytic behavior upon reducing the pH value of surrounding media to 5.4, which is characteristic of the endosomal compartments. Likewise, these pH-responsive NPs released MTX slightly faster at pH 5.4 than at physiological conditions. This NP feature might be a promising approach to achieve a greater and more specific drug release in cancer cells, thanks to its likely capacity to respond to the pH gradients existing in tumor tissue and intracellular compartments. The in vitro antitumor assays, using MTT and NRU as viability endpoints, demonstrated that MTX-loaded PCL-NPs have higher antiproliferative activity than free drug in MCF-7 cells and, to a lesser extent, in HepG2 cells. Noteworthy is that this same behavior was also markedly observed at mildly acidic conditions (pH 6.6), characteristic of the tumor microenvironment. Therefore, the overall results evidenced the pH-responsive properties of the designed nanocarrier, together with its greater in vitro cytotoxic activity compared to the non-associated drug, suggesting, thus, that this nano-based formulation could be promising for an innovative and more efficient antitumor therapy.
Acknowledgements: Capes-Print Financial code 001; CNPq for the Grant 401069/2014-1 and for the Postdoc fellowship.
Masaryk University, Czech Republic
Laser Ablation Synthesis (LAS) of Ge-Sb, Ge-Te and Sb-Teclusters
Mr. FeiHuang completed his bachelor's degree in 2011 and then he worked in an oil company for three years. He continued to pursue a master's degree and graduated in 2017 from Xi'an Shiyou University,Xi'an,China. Presently, he is PhD student at Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 62500 Brno, Czech Republic.
Statement of the problem:Germanium-Antimony-Tellurium (GST) is one of the most important phase-change-memory material.The Ge2Sb2Te5 bulk material has been studied by using mass spectrometry in our laboratory an recent detailed review of this phase change non-volatile memories is available. Here, we deal with the binaries (Ge-Sb, Ge-Te, Sb-Te) forming the ternary GST system. Laser ablation synthesis (LAS) can efficiently generate clusters from the mixture of elements and simultaneous use of a Time-Of-Flight (TOF) mass spectrometer (MS)determines the clusters composition. The methodology has already been shown to be a powerful method to study the formation of various clusters from inorganic compounds, glasses and/or mixtures.
The aim of this work is to use mass spectrometry following in details the formation of the binary clusters during LASin order to cover wide concentration ranges and to contribute further to the knowledge of these materials.
Methodology & Theoretical Orientation:The formation of binary GemSbn, GemTeo, and SbnTeo clusters generated by LAS from binary Ge-Sb, Ge-Te, and Sb-Te mixtures of elements was studied and stoichiometry of clusters was determined (cf. Fig.1). Structure of individual clusters generated from a mixture of elements was discussed.
Findings: i) LASwas found as a suitable method to generate binary clusters of GST material components. ii) Via computer modeling complicated isotopic patterns of clusters can be resolved, iii) Composition of clusters might represent partial structural fragments of the phase-change material. The results enable to understand structural motifs of the GST materials and the findings obtained can contribute to the proposal of new, more efficient phase-change memory materials.
Fig.1 Scheme of MS analysis
State Research Institute Center for Physical Sciences and Technology, Lithuania
Functionalization of iron oxide-based magnetic nanoparticles with gold shells
PhD student Agn? Mikalauskait? graduated from the Master of Science in Nanomaterial Chemistry and started Ph.D. in Chemistry in direction 03. During this period, the results of the master’s studies and doctoral studies were summarized and published in 5 scientific publications in Web-of-sci magazines with a citation index. Average index of quoted articles > 2.0. Also, the results of the last 3 years of research work have been presented at 9 international conferences, of which 5 orals in France, Germany, Lithuania and 4 stands in Lithuania. Scientific qualification upgrading in international schools related to the doctoral program: Portugal, VII Hands-on Course in Sample Preparation Using Nanoparticles for Proteomics. June 27-29, 2017 (4 days), BASF Summer School in Germany, 133rd International Summer Course August 21-26, 2017 Duration (week) and 1-month internship in Italy, Modena, Modena University of Reggio Emilia, Faculty of Physics and Nanosciences, Prof. The Marco Affronte Laboratory, which has been trained to characterize the objects of research, equipment for the detection of highly qualified magnetic properties.
This chapter is aimed at reviewing the methods reported to date for covering of magnetic iron oxide-based nanoparticles (NPs) with gold species and shells have found numerous applications in the recent nanomedicine as biocompatible materials for magneto hyperthermia, photothermal therapy, fluorescent and computed tomography imaging. Furthermore, through coating of magnetic NPs with gold their chemical and colloidal stability can be significantly improved allowing constructing a versatile platform for further NPs functionalization with antibodies, drugs, aptamers, and fluorescent agents.
Various studies have established the fact that a direct coating of magnetic NPs via electroless deposition using typical reducers such as sodium borohydride or citric acid is frequently problematic due to formation of gold crystallites in the solution bulk. To overcome this drawback, several methods for deposition of gold directly or through the intermediate layer onto the surface of magnetic NPs have been proposed during past 15 years. However, the reported approaches are mainly devoted to covering of magnetite (Fe3O4) and hematite (?-Fe2O3). Therefore, our recent findings dealt with these and other iron oxide-based, e.g. cobalt ferrite, NPs are presented in more detail. Contrary to the previous works reported the formation of continuous Au0 nanoparticulate shells, we succeed in the decoration of magnetic NPs with numerous Au0/Au+ quantum dots (QDs) contributing to their prospective future applications. In addition to presentation of reported to date gold deposition techniques, an attempt was made to discuss shortly the possible application trends of these core-shelled NPs.
Recently, gold-shelled iron oxide-based NPs are widely used for biological treatments and medical investigations because of their super paramagnetic behavior, non toxicity, chemical stability in various fluids and biocompatibility as well as capability to interact with the specific ligands, such as proteins, antibodies, drugs, nucleic acids, etc. Taken together, uniformly sized gold-coated magnetic NPs possess a great potential for tumors detection, anticancer therapy, immunogenicity and analytical sensing. Besides, the attached gold due to collective oscillation of free electrons in a continuous band structure can demonstrate crystallite size dependent plasmonic resonance band sensitive to the microenvironment. As a matter of a collective magnetic and optical behavior, a variety of new applications of gold-coated magnetic NPs were reported during the past decade.
Figure 1. TEM images of the CoFe2O4@Au NPs (a) and gold products remaining after CoFe2O4@Au NPs etching in the HCl (1:1) solution for thinner (c) and thicker (d) shells. In (b) the SAED spectrum taken from the scope of gold-coated cobalt ferrite NPs.
Angel Jimenez Chavez
National Autonomous University of Mexico, Mexico
B19 parvovirus-like particles as a delivery system of neoepitopes to prime cellular immunity against triple negative breast cancer
Angel Jimenez is an experimental biologist who has specialized in the search for new treatments for cancer, showing a special interest in the relationship between the immune system and cancer. He is currently studying his doctorate at the National Autonomous University of Mexico, focuses on the production and characterization of parvovirus B19 virus-like particles assembled in cell-free environment as antigen delivery systems to dendritic cells in lymph nodes for personalized immunotherapies, using a murine model of triple negative breast cancer.
Statement of the Problem: Triple negative breast cancer (TNBC) continues to be a major health problem which lacks molecular targets for therapy. The neoepitopes may represent a viable option for the induction of antitumor immune responses in TNBC. When used in the form of peptides or RNA neoepitopes have shown to be capable of inducing immune responses associated with improved clinical responses, nevertheless, limitations such as low immunogenicity and induction of tolerance remain. Virus-like particles (VLPS) of parvovirus B19 may be used as an alternative antigen delivery system. In this work, we designed and evaluated the therapeutic effect of chimeric B19 VLPs with multiple neoepitopes of the 4T1 cell line in the 4T1-induced breast cancer model.Methodology: Balb/c mice of 6-8 weeks with breast tumors received 4 therapeutic immunizations with chimeric VLPs, native VLPs, vehicle, or VLPs plus adjuvant; and tumor growth, lung macro-metastasis and specific immune responses were evaluated. Findings: Our results showed that therapeutic administration of multi-epitope chimeric-VLPs with and without adjuvant were able to significantly delay the tumor growth with respect to the vehicle and the native VLPs, chimeric VLPs significantly decreased the number of macro-metastasis in the lung in mice immunized. The analysis of the cell populations showed a decrease of the MDSC in the groups co-administered with the adjuvant, moreover, specific responses of CD8 and CD4 T lymphocytes towards the neoepitopes were induced in inguinal node. Besides, these CD8 T lymphocytes were positive to the production of granzyme B. Our results show that the use of VLPs-B19 as a delivery system of neoepitopes can induce specific cellular responses able to impact tumor growth and lung macro-metastasis in vivo, so they could be a good option as delivery system for antigens in personalized immunotherapy.
Non-toxic fluorescent silica Nanoparticles for observation of the living cell
Herein we report a novel synthesis yielding monodisperse fluorescent silica nanoparticles (SiNPs), with Fluorescein or Rhodamine-B incorporated within the core. Our nanoparticles are characterized by excellent photo-bleaching resistance. Illuminationwith a monochromatic laser light (wavelength λ=561 nm and power=38 mW), via continuous wave method, of a nanoparticle sample causes the loss of only 33% of the nanoparticles’ fluorescence intensity during 60 hours of illumination. This result is particularly important in bioimaging techniques, resulting in higher stability times and the possibility of use of lower SiNPs concentrations when performing measurements.
Moreover, our nanoparticles are non-toxic and highly biocompatible. A decline in cell vitality was not observed when Hela cells were incubated with PEG-coated silica nanoparticles containing Rhodamine-B. Nanoparticles were uptaken and remained in cells during following generations. Cells maintained high viability and proliferation potential for at least 14 generations after exposure. Due to their low cytotoxicity our PEG-coated silica nanoparticles are suitable for use in living cells and microorganisms.
Good solubility in aqueous environments is another important advantage of the presented nanomaterial. The described nanoparticles are characterized by prolonged stability, which exceeds 6 months at room temperature in aqueous solutions. The lack of toxic, commonly used stabilizers, such as azides, is especially beneficial in case of biological, biochemical and medical research.
These qualities of the nanoparticles make them potentially suitable for various biological and medical applications.
Fig. 1. Wide-field phase contrast and epifluorescence microscope pictures of
Masaryk University, Czech Republic
Interaction of Black Phosphorus (phosphorene) with smallmolecules and peptidesin MALDI TOF MS
Mr. Govinda Mandal, a resident of Mahottari, Nepal,graduated his B. Sc. in Microbiology from Tribhuvan University, Nepal and M. Sc. in Pharmaceutical Chemistry from HNB Garhwal University, India. He has more than 8 years of experience in Pharmaceutical Industries. He worked from basic analyst to higher Quality Management level (QC Manager, HOD). Presently, he is studying his PhD at Department of Chemistry, Faculty of Science, Masaryk University, A14/326-Kamenice 753/5, 625 00 Brno, Czech Republic.
Statement of the Problem:Black phosphorus (BP) represents the most stable allotrope (Fig. 1)withunique physico-chemical properties and with highnumber of bio-medical applications1.We have shown previously that phosphorusis an effective calibrant for MS analysis of complex biological samples2. In MALDI TOF MS, the BP selectively increases the ionization of some peptides3, 4. This phenomenon is not sufficiently explained so far. Here we address the mechanism of such altered ionization by combining BP and model peptide mixtures or relevant low mass molecules, such ascis-platinum and/or ruthenium complex ([RuClCp(mPTA)2](OSO2CF3)2).
Methodology & Theoretical Orientation:UV-Visible spectra were measured using UVmini-1240 Spectrophotometer, Shimadzu.Mass spectra were recorded (5 Hz frequency, pulsed width 3 nanoseconds) usingAXIMA CFR (nitrogen laser 337 nm, reflector), Kratos Analytical Ltd. The laser energy was selected from 0 to 180 a.u. (arbitrary units).Analyses were carried out in linear/reflectron positive/negative ion modes.
Findings:We studied adsorption of small peptidesand other low mass molecules like cis-platinum or Ru-complexon BP or on its single layer i.e. phosphorene (an analogue of graphene) surface.We found that BP interacts with different molecular moieties and affects the desorption energy. We propose, that such molecular interactions may be useful for more specific ionization and selective enrichment of the mass spectra with otherwise hardly ionizable molecular species. BP-
mediatedcommon MALDI matrices are promising materials for MS-based biotyping applications, ranging from metabolomics discrimination to complex bio-industrial scenarios, such as cell culture quality control5.
In summary, selective interactions of BP alter the ionization of peptides and other low mass molecules, and these phenomena may allow for more sensitive/selective MS detection. The BP-mediatedchanges depend on molecular structure of the partner compound, e.g. on number of aromatic rings or degree of saturation, areresulting in altered ionization in MALDI TOF MS.
Fig. 1: Structures of some phosphorus allotropes
Donghua University, China
Improving permeability, stability, and compatibility in the chemo-sensor and applied in bio-imaging
Octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) with amine-containing poly acryl amide (OV-POSS co-poly (acryl amide)) give a new fluorescent polymeric chemo sensor with fully water solubility. It shows better selectivity for Fe3+ in water solution over a wide detection range (pH=4-10). The incorporation of Fe 3+ to OV-POSS co-poly (acryl amide) results in a significant with fluorescence enhancement in water solution over other metal ions. Moreover, it was found that the system possesses low-cytotoxic, good permeability, high stability, and compatibility. Hence, it can be applied in bio-image successfully with bright blue fluorescent. Additionally, visible color change to the naked-eye from colorless to bright yellow can be observed directly when Fe3+ was added into chemo-sensor OV-POSS co-poly (acryl amide) compared with other metal ions.
Gediminas Technical University, Lithuania
Ultra-small methionine-capped Au0/Au+ nanoparticles as efficient drug against most dangerous bacteria
Mr. Rokas Zalneravicius received his B degree in Bioengineering at Vilnius Gediminas technical university in 2013 and Magna cum laude M degree in Chemistry of nanomaterials at Vilnius university in 2015. In 2017, he received Theodor Grotthuss memorial stipend for the academic achievement. He is currently pursuing his PhD degree at the Center for physical sciences and technology, Department of electrochemical material sciences, Laboratory of nanostructures in Vilnius, Lithuania. His research interest include antimicrobial surfaces and materials, catalysis, nanomaterials and 2D nano-composites for sensing applications.
It is commonly accepted that contrary to silver, gold in the metallic state is highly stable, biocompatible, and not cytotoxic even in the nanoparticulated size. Au nanoparticle antimicrobials render the grafted drug molecules, such as ampicillin, peptides or zwitterionic ligands. On the other hand, antimicrobial behavior of gold ions is well-known, has been widely investigated, and well-reviewed in Djuran and Glišic papers. According to the some recent reports, Au0 NPs reduced down to the nanocluster size, e.g. ≤2.0?nm in diameter, may also exhibit the antimicrobial activity against some fungi and bacteria strains. For example, Zheng et al. synthesized and tested 6-nm sized Au0 NPs and ≤2.0-sized gold nanoclusters both templated and protected with the 6-mercaptohexanoic acid. Although these NPs possessed quite similar surface zeta-potential, a remarkable antimicrobial efficacy has been established just for nanoclusters against S. aureus and E. coli killing roughly from 95 to 96 % of their population. Besides, it was concluded that the antimicrobial effect is not derived from the surface ligand and its content. On the contrary, Zhang et al. reported that cationic ligands of gold NPs contributed to their antimicrobial activity. This effect has been attributed to the strong ionic interaction with the bacteria indicating that positively charged ligand molecules of Au NPs are responsible for the bacteria membrane permeability increase.
Inspired by these works, in this study, we synthesized and tested ultra-small gold and gold-functionalized magnetite NPs comprised of Au0/Au+ for possible inactivation of multi-drug resistant bacteria. To the best of our knowledge, the antimicrobial behavior of ultra-small gold NPs stabilized with the amino acid has not been investigated against the most dangerous microorganism such as methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Salmonella enterica. For comparison, the antimicrobial efficacy of the magnetite NPs decorated with Au0/Au+ species were also tested.
Jay Robert Laceda
Polytechnic University of the Philippines, Philippines
Synthesis of nanocomposite based on impregnated bimetallic nanoparticles on activated carbon for adsorption of cadmium(ii) in aqueous solution
In this study , bimetallic Copper-Nickel nanoparticles impregnated on activated carbon (CuNiAC)nanocomposites was synthesized using sodium citrate as reducing agent and Poly(vinyl) alchohol as stabilizer. It was characterized using Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The synthesized CuNiACnanocomposites has the size range of 21-71 nm of impregnated nanoparticles and was used as the adsorbent for removal of Cadmium (II) in aqueous solution. The adsorption of Cadmium (II) in aqueous solution using CuNiACnanocomposites and commercial activated carbon was carried out so as to comparatively evaluate the effectiveness of both adsorbent for the purpose of removing Cadmium (II) from aqueous solution. The adsorption experiment performed indicated the suitability of using the synthesized CuNiACnanocomposites compared to the commercial activated carbon (AC) having the maximum percentage removal of 49.75 % in its highest dosage compared to the 21.57% removal percentage obtained by AC’s highest dosage. In terms of contact time the CuNiAC has the highest removal percentage which is about 13. 35% compared to 11.0 % removal percentage obtained by AC. This improved removal percentage of R20CuNiAC can be associated with the presence of additional adsorption sites provided by nanoparticles and presence of other functional groups on CuNiACnanocomposites as detected by Fourier transform infrared spectroscopy.