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Nanotechnology Spotlight – Latest Articles

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Showing Spotlights 1041 - 1048 of 2140 in category (newest first):


A biophysical perspective of understanding nanoparticles at large

nanoparticlesAt the core of research efforts to determine the impact of synthetic nanoparticles on the environment and living systems is a fundamental understanding of the interactions between man-made nanoparticles and natural living systems that have evolved over millions of years. To describe nanoparticles at large, it may be beneficial to acknowledge that 1) biological systems are part of the food chain and therefore an essential component of the ecosystems and 2) collaborations are essential for such interdisciplinary research. Researchers have now presented a biophysical perspective that describes the fate of nanoparticles in both the aqueous phase and in living systems.

Posted: Mar 16th, 2011

Millimeter-sized monolayer crystals open the door to single crystal organic nanoelectronics

two-dimensional_crystalAlthough organic semiconductor materials cannot yet be packed as densely as state-of-the-art silicon chips, they require less power, cost less and do things silicon devices cannot: bend and fold, for example. Once perfected, organic semiconductors will permit the construction of low-cost, spray-on solar cells and even spray-on video displays. Notwithstanding tremendous progress in the area of organic electronics, several major challenges still exist. To address these challenges, researchers have combined organic electronics with nanoelectronics and developed the first 2D crystal of organic semiconductors on the millimeter scale, the thickness of which is only a single molecular layer, but with perfect long-ranged crystalline order.

Posted: Mar 15th, 2011

Perspectives for live cellular biosensing with nanowire arrays

nanowires_and_cellsIn order to get a true picture of the processes and events that take place inside unmodified, living cells, probing techniques need to be non-destructive, noninvasive and in real-time. Due to their small dimensions, high-aspect ratio nanomaterials such as nanofibers, nanowires and carbon nanotubes are ideal for cellular applications since they can cross the cell membrane without causing significant damage. In particular, semiconductor nanowires attract a lot of interest because of their uniformity, reproducibility and possibility of fine-tuning their intrinsic properties - physical dimensions, crystal structure, electrical and optical properties, etc. Researchers have now shown, for the first time, the spontaneous and close interface of arrays of vertically aligned indium arsenide nanowires with two relevant cell lines, human embryonic kidney cells and rat embryonic dorsal root ganglion neurons.

Posted: Mar 14th, 2011

Biomedical applications of nanodiamonds might require more caution

nanodiamondsOwing to their large surface area, strong infrared photoluminescence and magnetic properties, nanodiamonds are promising for various biomedical applications, including as drug/gene carriers and alternatives to the current bio-imaging platforms. However, the biomedical applications will hardly be realized unless the potential hazards of nanodiamonds to humans and other biological systems are ascertained. The biocompatibility of nanodiamonds at the cellular level has been confirmed by many independent studies. Following these earlier cytotoxicity studies, many groups have used nanodiamonds and their functionalized derivatives for drug/gene deliveries. In spite of the earlier reports that nanodiamonds are biocompatible at the cellular level, researchers have now demonstrated in a new study that nanodiamonds can activate DNA repair proteins in embryonic stem cells, suggesting possible DNA damages.

Posted: Mar 10th, 2011

Chemical growth methods are reason for silicon nanowires' poor photovoltaic performance

nanowiresNanowires - particularly those of silicon - promise great potentials for high-efficiency, low-cost solar energy conversion. This promise has not yet been met by experimental evidence, raising fundamental questions whether silicon nanowires are intrinsically disadvantaged and whether the photovoltaic research community should continue working on this material. Despite intense efforts, the performance of silicon nanowire-based solar cells remains significantly lower than what has been achieved for bulk silicon or micrometer-scale wires. The gap between the predicted performance and the inability to deliver raises an important question with regard to the origin of this problem. New research shows that the poor performance is not a result of the nanowire morphology, but is intrinsic to the growth chemistry.

Posted: Mar 9th, 2011

Impact of nanoscale topography on genomics and proteomics of adherent bacteria

One of the main basic bacterial survival strategies is the colonization of a surface and the consequent growth as biofilm community, which is embedded in a gel-like polysaccharide matrix. In spite of its swimming/planktonic counterpart, such sessile adherent bacterial population represents an excellent life-support system. A biofilm like bacteria community is in fact highly resistant to almost any classical bactericidal and bacteriostatic tools, ranging from broad-spectrum antibiotics to UV-rays, disinfectant, heat, and so on. Thus, the design of biomaterials with active antibacterial and self-cleaning properties represents a good opportunity for solving the biofilm associated infections. One of the main goal is avoiding one of the first necessary steps required for the biofilm growth, namely the bacterial adhesion onto the target surface.

Posted: Mar 8th, 2011

Microfluidic, label-free, high-throughput nanoparticle analyzer

nanoparticle_analyzerCurrently, the most common methods for sizing nanoparticles extract data from bulk measurements. These techniques are inherently averaging and so are unable to effectively resolve mixtures of different-sized particles. While individual nanoparticles can be sized using electron microscopy, this approach is time-consuming and of little utility in assembling significant population statistics. Researchers have now developed a microfluidic device for the all-electronic analysis of complex suspensions of nanoparticles in fluid. This device is capable of detecting and sizing individual and unlabeled particles as small as a few tens of nanometers in diameter at rates estimated to exceed 100,000 particles per second.

Posted: Mar 7th, 2011

Multifunctional nanobioprobes detect and isolate multiple types of cancer cells

fluorescent_microscope_imagesMultifunctional nanomaterials have become widely researched in nanomedicine with the goal of developing highly accurate probes for detecting and isolating cancer cells. Of particular interest here are magnetic nanoparticles, which offer the capability of cell isolation from original or enriched samples without the use of centrifugation or filtration. In particular, the combination of fluorescent quantum dots and magnetic nanoparticles into single nanospheres to obtain fluorescent-magnetic bifunctional nanospheres has created the potential for broader applications in biomedicine and in clinical diagnosis. In new work, researchers have now expanded this technique to multiplexed assays. They demonstrated the ability to detect and collect multiple types of cancer cells, such as leukemia cells and prostate cancer cells, from mixed samples within 25 minutes by using a magnet and an ordinary fluorescence microscope.

Posted: Mar 4th, 2011