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Nanotechnology Spotlight – Latest Articles

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Showing Spotlights 105 - 112 of 167 in category Sensors, Sensing Applications (newest first):


Counting single molecules inside nanodroplets

nanodropletsA lot of the scientific knowledge in chemistry and biology comes from experiments on ensembles of molecules by which a vast number of duplicate behaviors are investigated and averaged responses are recorded. Especially the ability to make measurements at the single molecule level provides crucial information about biological and chemical systems. This research depends on molecular manipulation technologies that are able to isolate individual molecules and sequentially transport them for measurement and, potentially, manipulation. To this end, generation and manipulation of small, highly monodisperse droplets have received a lot of attention in the biotech community recently. Using a simple droplet generator chip, scientists can generate millions of droplets in a short amount of time. Each individual droplet is isolated from another droplet, hence, meaning that a million droplets constitute a million individual microreactors running a million reactions simultaneously.

Posted: Nov 25th, 2009

Traffic monitoring with a self-sensing concrete nanotechnology road surface

asphalt"Researchers have developed a self-sensing nanotechnology composite material for traffic monitoring by using piezoresistive multi-walled carbon nanotubes as an admixture. In experiments, they studied the response of the piezoresistive properties of this composite to compressive stress and they investigated with vehicular loading experiments the feasibility of using self-sensing CNT/cement composite for traffic monitoring. This nanocomposite cement has great potential for traffic monitoring use such as in vehicle detection, weigh-in-motion measurement and vehicle speed detection. An interesting aspect of this work is that, from the eventual traffic application's point of view, the pavement itself would become the traffic detection, thus eliminating the need for separate traffic flow detection sensors.

Posted: Oct 9th, 2009

Nanotechnology sensor detects living bacteria at ultralow concentrations

nanobiosensor"In their effort to develop a fast, sensitive, selective, inexpensive, and easy-to-use method for detecting and quantifying pathogenic bacterial cells, researchers in Spain have now demonstrated a carbon nanotube based potentiometric biosensor for selectively detecting one single colony-forming unit of the bacterium Salmonella Typhi in close to real time. The most important strength of this biosensor is that simple positive/negative tests can be carried out in real zero-tolerance conditions and without cross reaction with other types of bacteria. The ease with which measurements are taken in potentiometric analysis opens the door to greater simplicity in microbiological analysis.

Posted: Oct 5th, 2009

Nanotechnology sensor can 'smell' lung cancer in exhaled breath

breath_analysisAccording to the World Health Organization, lung cancer is the leading cancer-related cause of death, accounting for 18 percent of cancer deaths and killing about 1.3 million people worldwide every year. Conventional diagnostic methods for lung cancer occasionally miss tumors and they are costly and unsuitable for widespread screening. Breath testing is a fast, non-invasive diagnostic method that links specific volatile organic compounds (VOCs) in exhaled breath to medical conditions. However, these techniques - gas chromatography/mass spectrometry, ion flow tube mass spectrometry, laser absorption spectrometry, infrared spectroscopy, polymer-coated surface acoustic wave sensors and coated quartz crystal microbalance sensors - are expensive, slow, and require complex instruments. A multidisciplinary research team at Technion - Israel Institute of Technology have now demonstrated a highly sensitive, stable, relatively inexpensive, and fast-response nine-sensor array that consists of gold nanoparticles functionalized with different organic groups that respond to various VOCs that are relevant to lung cancer.

Posted: Aug 31st, 2009

Bio-interface nanosensor visually reports damage to a material

FRET_nanosensorThe term bio-interface describes the boundary between synthetic materials such as plastics, and biological systems. This rapidly growing research area, where biology and material sciences overlap, is creating new opportunities for the design, synthesis, and optimization of biologically-enabled and biologically-inspired materials. It involves manufacturing and characterization of functional surfaces for specific interactions with bio-systems and studies of the molecular and kinetic processes occurring at such interfaces, ranging from small molecule and biomolecular interactions, to cell adhesion, differentiation and tissue formation at the interface. For example, the incorporation of proteins into polymers can result in hybrid materials that combine the properties of the polymer as a cost-effective and easy to process material with the highly evolved biological functionality of the protein, enabling new concepts for construction of sensors and biomedical materials. While researchers so far have been focusing on altering the properties of a polymer by adding the functionality of a biomolecule, a group in California has now demonstrated the reverse situation, where changes in the polymer can alter the properties of the protein.

Posted: Aug 11th, 2009

Biosensors printed on bioactive paper

biopaper_sensorDeveloping bioassays that are simple, portable, disposable and inexpensive will provide important tools to rapidly detect toxic substances. This technology could also be extremely useful in monitoring environmental and food-based toxins in remote settings such as less industrialized countries where these tools are essential for the first stages of detecting disease settings and where the time and expense of using sophisticated instrumentation would be prohibitive. To that end, researchers have developed simple, portable, disposable, and inexpensive paper-based solid-phase sensors to run multiple bioassays and controls simultaneously. Bioactive paper is any low-cost and easy-to-use paper product laced with biologically active chemicals that provides a rapid way to detect toxins like E. coli bacteria and salmonella, or pathogens such as SARS or influenza.

Posted: Jul 24th, 2009

Nanofluidics meets nanoplasmonic sensing

nanoplasmonicsControlling surface plasmons has become increasingly attractive for optical signal processing, surface enhanced spectroscopy and sensor nanotechnology. For instance, the role of surface plasmon resonance (SPR) on resonant transmission through nanohole arrays has motivated their application as surface-based biosensors. New work by a team of scientists in Canada has combined nanofluidics and nanoplasmonics for SPR sensing using flow-through nanohole arrays. This new format enables rapid transport of reactants to the active sensing surface and the array serves as a sieve. That is, the flow-through array efficiently collects and detects biomarkers from a very small volume of fluid.

Posted: Jul 17th, 2009

Fluorescent gold nanoprobes for real-time detection of reactive oxygen species

fluorescent_ROS_imagingEnvironmental and behavioral factors may lead the body to produce superoxide radicals known as reactive oxygen species (ROS) that could cause cell damage through oxidation. Oxidative stress from ROS is implicated in aging and most diseases including cancer, heart disease, liver fibrosis, neurodegenerative diseases, autoimmune disorders. An excess of these reactive molecules can lead to oxidative stress and cellular damage, and toxicologists have identified ROS generation as a likely mechanism of nanoparticle toxicity. Since ROS plays an important role in various pathogenic processes, it has been recognized as an early indicator for cytotoxic events and cellular disorders. However, conventional chemical ROS probes have not fulfilled the rising need of in vitro and in vivo analysis of ROS generation due to auto-oxidation problems and poor specificity and sensitivity. Scientists in South Korea have now demonstrated a novel ROS-sensitive gold nanoprobe prepared from bio-inspired immobilization of fluorescein-labeled hyaluronic acid onto the surface of gold nanoparticles. This probe is highly stable under exposure to natural light and laser sources and extremely sensitive and specific to certain oxygen species.

Posted: Jul 2nd, 2009