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Showing Spotlights 1049 - 1056 of 2140 in category (newest first):

 

Unique fabrication approach for wafer-scale plasmonic nanosensor platform

nanowire_structuresNo matter how precise nanosensors and -probes become, bridging the huge gap between nanoscale dimensions and macroscale structures (e.g., wafer size) has been a tremendous challenge for researchers. Researchers in the U.S. have demonstrated a generalized hybrid nanofabrication concept that combines both top-down (deep-UV lithography) and bottom-up (controlled lateral epitaxial growth and atomic layer deposition) fabrication techniques. This unique methodology allows the development of reproducible nanostructured platforms that contain controlled sub-10 nm gaps between plasmonic nanostructures over an entire wafer, i.e. a 6-12 inch area. This approach opens new horizons to more widespread applications in chemical sensing and biomedical diagnostics.

Posted: Mar 2nd, 2011

Bacteria as live cargo shuttles for nanofabrication

bacteria_cargoshuttleBacterial propulsion systems are intriguing for nanotechnology researchers because nature has already solved most of the problems that they are still struggling with in designing molecular motors and other self-sustained nanoscale actuating systems. Indeed, it has turned out to be very challenging to even move sub-micron scale structures in well directed paths, especially under biologically friendly conditions. In previous work, researchers have already shown how large numbers of bacteria can propel larger sub-mm scale structures. And in a 2005 paper, researchers demonstrated a method of using the power generated by biological motors to transport microscale loads while leaving these motors in intact cells. Scientists at Johns Hopkins University have now demonstrated a strategy to autonomously move nanostructures in well defined paths by enabling individual bacteria-cargo conjugates. They showed how approximately 500 nm-sized structures deposited on substrates can be attached to individual bacteria and when released, the bacteria stay motile and ferry this cargo.

Posted: Mar 1st, 2011

Full-color quantum dot displays are getting within reach

displaysQuantum dots, because they are both photoluminescent and electroluminescent and have unique physical properties, will be at the core of next-generation displays. Compared to organic luminescent materials used in organic light emitting diodes (OLEDs), QD-based materials have purer colors, longer lifetime, lower manufacturing cost, and lower power consumption. Another key advantage is that, because QDs can be deposited on virtually any substrate, you can expect printable and flexible displays of all sizes. To date, the integration of QDs into a full-color LED structure has not been possible due to the difficulty in patterning individual red-green-blue (RGB) QDs onto the pixelated display panel. Now, a Samsung team has demonstrated a novel transfer printing approach which enables fine patterning of high-quality QD films for large-area (4-inch diagonal), full-color displays mounted on glass as well as on flexible plastic substrates.

Posted: Feb 28th, 2011

Functionalized nanochannels can detect single-mismatched DNA sequence

DNAA Single Nucleotide Polymorphism (SNP) is a single nucleotide replacement in a DNA sequence - occurring when a single nucleotide (A, T, C, or G) in the genome differs - which can result in different reaction by people to pathogens and medicines. Detection of these SNPs is becoming increasingly important with the move towards more personalized healthcare. Researchers are therefore working hard in developing biomedical lab-on-chip sensors that allow the fast detection of SNPs in DNA using only very small samples of a patient's blood. Already, nanoscale detection techniques such as synthetic nanochannels are being used for DNA detection by specific DNA hybridization with molecular probes immobilized on the nanochannel walls. However, the preparation of these sensors is not easy and specific functionalization at the wall surface remains a critical issues. Researchers have now introduced a new concept of DNA-based molecular recognition agents which allows detecting SNPs with very high precision and efficiency.

Posted: Feb 25th, 2011

Novel quantum dot nanocomposites reconcile blinking/tracking issues

quntum_dot_blinkingResearchers are faced with a paradox in quantum dot-based particle/molecule tracking: on one hand, blinking is a problem for quantum dot-based tracking as it breaks up tracking trajectories; on the other hand, blinking is also a very useful indicator as it offers the best - and often only practical - in situ indication of aggregation status. Thus, when a researcher conducts a tracking experiment, s/he is annoyed by blinking but at the same time would be equally disappointed if blinking was not present to confirm single, or near single, particle status. Previous strategies to manipulate blinking dynamics involve changing the structure (surface or core chemistry) of a quantum dot. Scientists have now taken a fundamentally different approach: quantum dots employed remain unchanged.

Posted: Feb 24th, 2011

A nanosensor platform for direct detection of a cancer biomarker in blood

nanoporous_membraneResearch to develop sensors that can rapidly detect biomarkers (associated with certain diseases such as cancer) in whole blood, ideally at the point of care, and when the protein biomarker level in blood is very low (i.e. the disease is in an early stage) is being advanced by nanosensor technology. In a recent development, scientists in Spain have developed a rapid nanochannel-based immunoassay capable of the filtering and subsequent detection of proteins in whole blood without any sample preparation. This is the first time that a simple assay to detect proteins in whole blood using nanochannels has been achieved. This is a simple device and set-up that allows nanochannels to achieve such the double functionality of filtering and detection on the same platform.

Posted: Feb 23rd, 2011

Nanolasers grown on silicon allow bottom-up nano-optoelectronic integration

nanolaserSilicon and III-V semiconductors are the respective foundations of modern electronics and photonics. Integrating these materials is essential for achieving new optoelectronic functionality and faster computer architecture. However, lattice mismatch and high III-V growth temperatures have prevented such integration thus far. Most importantly, in order to be able to take advantage of today's massive silicon infrastructure, integration must be compatible with current complementary metal-oxide-semiconductor (CMOS) infrastructure and process flows. Researchers at UC Berkeley have overcome these obstacles by developing a way to grow III-V nanolasers on silicon, demonstrating the potency of bottom-up nano-optoelectronic integration.

Posted: Feb 22nd, 2011

Nanotechnology-based solutions for oil spills

The recent oil spill in the Gulf of Mexico is widely acknowledged to be among the worst ocean oil spills in world history. Inevitably, the spill has once again raised serious concerns worldwide about the likely environmental impact of such catastrophic oil spills caused by oil tanker accidents at sea or mishaps during loading and unloading of oil from tankers at seaports. Numerous solutions have been proposed for dealing with the problem of oil spills. Conventional techniques are not adequate to solve the problem of massive oil spills. In recent years, nanotechnology has emerged as a potential source of novel solutions to many of the world's outstanding problems. Although the application of nanotechnology for oil spill cleanup is still in its nascent stage, there has been particularly growing interest in exploring ways of finding suitable solutions to clean up oil spills through use of nanomaterials.

Posted: Feb 21st, 2011