BSP :: Current Nanoscience Home Page

Contents

Editorial Pp.1-1
Atta-ur-Rahman

Nanocluster Optical Resonance Devices for Molecular Structure Transduction Pp.3-16
Jakob Haglmuller, Viacheslav Matyushin, Harald Rauter, Christian Mayer, Heinz Winkler, Georg Bauer and Thomas Schalkhammer
[Abstract] [Full text article]

Plasmonics – Towards Subwavelength Optical Devices Pp.17-22
Stefan A. Maier
[Abstract] [Full text article]

Tools of Nanotechnology: Electrospray Pp.23-31
Oleg.V. Salata
[Abstract] [Full text article]

Recent Advances in Ionic Liquids for Synthesis of Inorganic Nanomaterials Pp.33-40
Yong Zhou
[Abstract] [Full text article]

Nonvolatile Memory from Single-walled Carbon Nanotube-based Field Effect Transistors Pp.41-44
Sigen G. Wang, Paul J. Sellin, Qing Zhang and Dajiang J. Yang
[Abstract] [Full text article]

Nanosystems in Drug Targeting: Opportunities and Challenges Pp.45-62
Jaspreet K. Vasir, Maram K. Reddy and Vinod D. Labhasetwar
[Abstract] [Full text article]

Principles of Nanoflow Liquid Chromatography and Applications to Proteomics Pp.63-69
Pedro R. Cutillas
[Abstract] [Full text article]

Mimicking Biogenic Silica Nanostructures Formation Pp.71-81
Pascal J. Lopez, Clementine Gautier, Jacques Livage and Thibaud Coradin
[Abstract] [Full text article]

A Random Walk DNA Algorithm for the 3-SAT Problem Pp.83-87
Wenbin Liu, Lin Gao, Qiang Zhang, Guandong Xu, Xiangou Zhu, Xiangrong Liu and Jin Xu
[Abstract] [Full text article]

Development of Nano-Scale DNA Computing Devices Pp.89-93
Zhizhou Zhang, Chunhai Fan and Lin He
[Abstract] [Full text article]

Abstracts

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Editorial
Atta-ur-Rahman
[Full text article]

This is the first and historic issue of “Current Nanoscience”. In the last two decades and particularly in the last 10 years, nanoscience has evolved rapidly. Molecular analysis techniques are new being developed using nanocluster optical resonance devices. The optical properties of metallic nanostructures are being studied with the purpose of developing material systems for micro- and nano-optic devices. Electrospray is being used to generate nanoparticles and nanodots to allow separation according to their size, and to disperse them as nanomaterials for instance in mass-spectroscopy of biomolecules utilizing nano-electrospray. The synthesis of inorganic nano-materials is being facilitated by a growing understanding of the properties of ionic liquids. Single-walled carbon nanotube – based field effect transistors are being developed with good memory effects. Nano-systems (including nano-sized drug carrier systems, such as polymeric nanoparticles, liposomes, micelles and polymer-drug conjugates are being employed for targeting drugs to specific body sites. Nanoflow liquid chromatography is being applied successfully to applications in the fast growing field of proteomics. Nano-scale DNA computing devices are being developed which may one day replace silicon-devices with nano-scale molecular-based computational materials.

These and other exciting areas are covered in comprehensive reviews written by eminent experts. It is hoped that this journal will soon become the foremost scientific review journal in this rapidly developing field.

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Nanocluster Optical Resonance Devices for Molecular Structure Transduction
Jakob Haglmuller, Viacheslav Matyushin, Harald Rauter, Christian Mayer, Heinz Winkler, Georg Bauer and Thomas Schalkhammer
[Full text article]

Resonant enhancement of metal cluster light absorption (REA) is an effective means to set up novel nanooptical devices. The boosting of optical absorbance is achieved by a resonant four component system. A metal mirror, a polymer or glass type nano-distance layer, a reactive bio-molecule layer and a sub-monolayer of bound metal nanoclusters are employed. Decisive for these types of devices and sensors is the precise nanometric assembly that couples the local field surrounding a cluster with its mirror-dipole. Metal clusters (synthesized by chemical reduction or deposited by vacuum coating techniques), metal-dielectric shell clusters (synthesized by multiple shell deposition processes) as well as high quality tuning of the distance layer enabled us to precisely shift the readout of the device to any frequency in the visible and near IR range. Sensors show one to three narrow or broad-band reflection minima in the visible and/or infra part of the spectrum. These are tuned by adjustment of the geometric parameters of the setup (Fig. (1)).

Devices are used for detection of biorecognitive binding and monitoring structural changes of nucleic acids, proteins or analyte-recognitive polymers. The chip responds to the presence or absence of an analyte by a conformational change of the bio/polymer-transducer, thereby changing the cluster-mirror distance (or cluster distribution) and thus the optical absorbance and color of the chip. Disposable single step protein chips, DNA assays, RNA–conformation chips and polymer-artificial noses as well as complex arrays make use of the novel conformation-color transducer.

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Plasmonics – Towards Subwavelength Optical Devices
Stefan A. Maier
[Full text article]

Aspects of the optical properties of metallic nanostructures sustaining surface plasmon-polaritons are reviewed, focusing on differences with dielectric counterparts for the creation of functional nanoscale optical devices such as waveguides and resonators. The ability of plasmonic structures to confine light to volumes significantly smaller than the diffraction limit of light is discussed and a number of important applications are presented, with an emphasis on structures consisting of metallic nanoparticles. The important challenge of efficient excitation of surface plasmon-polaritons in a micro-optic framework is also addressed. A unified description of both plasmonic and dielectric photonic structures using quality factor and effective mode volume as figures of merit should allow for a clear choice of materials system for microand nano-optic devices.

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Tools of Nanotechnology: Electrospray
Oleg.V. Salata
[Full text article]

Liquids can readily interact with electric fields. Field-induced or injected charges in liquids interact with an external electric field causing liquids to move, break into drops or spray into jets or strings of fine droplets. One important case of liquid in the capillary deserves special mentioning as it serves as a basis of many and varied technological applications. An electric field acts on a liquid meniscus, counteracted by surface tension. In a strong enough field a cone is formed that emits a jet of liquid from its tip. This effect is used, for example, to coat car bodies by a thin uniform layer of paint. At the other end of the scale nano-electrospray has revolutionised mass-spectroscopy of bio-molecules. The ability of electrospray to repeatedly generate very small and uniform volumes of liquid makes it into one of the important tools of nanotechnology. Electrospray has been used to deposit ultra-thin films of inorganic, organic and biological materials, to generate nanoparticles and quantum dots, to sort them according to their sizes, and to help with dispersion and delivery of nanomaterials. This mini-review introduces basics of electrospray technology and summarises the diverse applications of electrospray in nano-sciences.

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Recent Advances in Ionic Liquids for Synthesis of Inorganic Nanomaterials
Yong Zhou
[Full text article]

Ionic liquids (ILs) are organic salts of low melting points with a wide range of liquidus temperature and intrinsically useful characteristics of negligible vapour pressure, thermal stability, high ionic conductivity and a large electrochemical window. As a green recyclable alternative to traditional organic solvents, the ILs have shown promise in the liquid/liquid extraction of organics from water and metal ions from solution, and separating isomeric organic compounds, selective catalytic processes for organic chemical reactions and solar cells and other electrochemical devices. In recent years, the advantages of the ILs in inorganic nanomaterial synthetic procedures have been realized and received more and more attention. In this brief review, the latest developments regarding the use of the IL as reaction medium for inorganic nanomaterials are outlined, mainly focused on (1) the preorganized structure of the IL as template effect for porous inorganic nanomaterials and (2) the intrinsic high charge and polarizability of the IL to create electrostatic and steric stabilization for metal nanoparticles and to favor phase transfer of the nanoparticles from water to water-immiscible solvent.

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Nonvolatile Memory from Single-walled Carbon Nanotube-based Field Effect Transistors
Sigen G. Wang, Paul J. Sellin, Qing Zhang and Dajiang J. Yang
[Full text article]

Nonvolatile memory from carbon nanotube-based field effect transistors (CNTFETs) was investigated in this paper. The CNTFETs were fabricated employing a single-walled carbon nanotube produced by arc-discharge technique, followed by the lift-off process. Hysteresis was clearly observed in the curve of the drain current versus gate voltage, which makes the CNTFET possible for a nonvolatile memory cell. It was also found that the environmental molecules including water and alcohol evidently affected the memory windows. The roles of the water and alcohol molecules in memory effect were discussed.

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Nanosystems in Drug Targeting: Opportunities and Challenges
Jaspreet K. Vasir, Maram K. Reddy and Vinod D. Labhasetwar
[Full text article]

The long cherished goal of targeting drugs to specific sites in the body, where the pharmacological action is desired and sparing other tissues has been actively pursued all these years. The concept of ‘magic bullets’ given by Ehrlich has now seen a metamorphosis to ‘magic wands’, in the form of targeted drug delivery systems. The magic, all due to the specific targeting ligands which guide the drug carriers to the molecular targets be it on cell surface or nuclear membranes. Nanosystems including the nano-sized (<1000 nm) drug carrier systems, such as polymeric nanoparticles, liposomes, micelles and polymer-drug conjugates are the vanguards of this ever-evolving field. Targeting drugs to specific sites, and maintaining pharmacologically relevant drug levels at the site for a period required for desired therapeutic action is what makes the nanosystems – the burgeoning magic wands. Substantial challenges still exist in terms of biological barriers. Nevertheless, the approaches like directly reaching the target using catheters, or using exogenous guiding mechanisms (magnetic fields and ultrasound), and exploiting the accessible targets on vascular endothelium are emerging as new and promising trends. It is conceivable, that despite all the formidable challenges, interplay of different disciplines ranging from engineering to biology will make the dream of drug targeting come true!

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Principles of Nanoflow Liquid Chromatography and Applications to Proteomics
Pedro R. Cutillas
[Full text article]

The low levels of endogenous proteins in biological samples and the large dynamic range of the proteome complicate global analysis of gene expression at the protein level. The use of liquid chromatography (LC) in analytical chemistry is well established. However, the relatively low sensitivity associated with conventional LC makes it unsuitable for the analysis of certain biological samples. Furthermore, the flow rates at which it is operated are not compatible with the use of specific detectors, such as electrospray ionization mass spectrometers. Therefore, due to the analytical demands of biological samples, miniaturized LC techniques were developed to allow for the analysis of samples with greater sensitivity than that afforded by conventional LC. In nanoflow LC (nanoLC) chromatographic separations are performed using flow rates in the range of low nanoliter per minute, which result in high analytical sensitivity due to the large concentration efficiency afforded by this type of chromatography. NanoLC, in combination to tandem mass spectrometry, was first used to analyze peptides and as an alternative to other mass spectrometric methods to identify gel-separated proteins. More recently, gel-free analytical approaches based on LC and nanoLC separations have been developed, which are allowing proteomics to be performed in faster and more comprehensive manner than by using strategies based on the classical 2D gel electrophoresis approach.

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Mimicking Biogenic Silica Nanostructures Formation
Pascal J. Lopez, Clementine Gautier, Jacques Livage and Thibaud Coradin
[Full text article]

Biomineralization processes are now fully recognized as inspiring systems for the design of new materials. In the case of silica, the formation of diatom shell or sponge spicule has attracted much attention in the last decade since it could provide key information to elaborate new hierarchically structured materials and nanodevices. In these two examples, the mineral phase is thought to be formed by the controlled assembly of nanoparticles generated in vivo from diluted precursor solutions, in the presence of biomolecular templates. The elucidation of biosilicification processes therefore relies on the understanding of biomolecules capacity to form and structure colloidal silica. Two different approaches have been developed. The first one starts with the extraction and identification of biomolecules present in silicifying organisms and then addresses the in vitro specific activity of these molecules towards silicon species. Alternatively, model macromolecules are used to understand the role of functionality and of structure on silica formation. This review aims at providing a critical overview of the most recent advances in these domains. Relevance for both the understanding of biosilicification process and the design of new bio-inspired nanomaterials are also discussed.

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A Random Walk DNA Algorithm for the 3-SAT Problem
Wenbin Liu, Lin Gao, Qiang Zhang, Guandong Xu, Xiangou Zhu, Xiangrong Liu and Jin Xu
[Full text article]

We present a randomized DNA algorithm for the 3-SAT problem based on the probabilistic algorithm proposed by Schoning. The basic idea of our algorithm is that the read of information is performed in linear DNA molecules, while the rewrite information is implemented in plasmid DNAs. Compared with previous works, our algorithm performs the flip of a variable’s value more easily and reliably, and the time complexity is also reduced to O(mn), where m is the number of clauses and n is the number of variables. Moreover, Schoning’s algorithm has been further improved recently for the case of 3-SAT by Hofmeister. We also demonstrate how to adapt this improvement in our new algorithm and the space complexity of our algorithm is then reduced to O[(4/3)^n-3m’ (7/3)^m’], where m’ is the number of the maximal independent clauses. Up to now, this is the most volume-efficient algorithm for the 3-SAT based on DNA computing.

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Development of Nano-Scale DNA Computing Devices
Zhizhou Zhang, Chunhai Fan and Lin He
[Full text article]

DNA computing employs DNA molecule as a main resource to fulfill computing tasks. However, the concept of primary DNA computing unit keeps obscure. It is recently realized that there are multiple forms of basic DNA computing units, all with the fundamental property of nano-scale DNA fragments of Waston-Crick pairing. In this review five non-exclusive types of the main DNA computing units were summarized one by one, and they are Adleman unit, Tiling unit, Rothemund-Shapiro unit, Ribozyme unit and Paun unit. Adleman unit is actually just basic Waston-Crick pairing/ligation, or a simplified version of DNA assembly; Tiling unit is from various DNA tiles, with assembly as computing process; Rothemund-Shapiro unit is Turing machine-like autonomous DNA automaton. Ribozyme unit is an endeavor that may first lead to protein enzyme-free DNA automaton. There is another special DNA computing unit called here as “Paun unit”, which is the membrane computing unit. It is not easy to comment which unit is most promising in the future, but studies on all these units will certainly promote DNA manipulation technologies and thus development of novel nano-scale DNA computing devices.