DNA Nanosensor Detects Disease
October 6, 2009 by admin
Filed under Featured, Ultrasonic
A portable instrument based on an ultrasensitive nanoscale sensor could detect bacteria in minutes, helping to catch infectious diseases early and prevent their spread. The simple, low-cost device should be available within three years, says Benjamin Miller, professor of dermatology and biomedical engineering at the University of Rochester Medical Center, and codeveloper of the sensor.
Right now, diagnosing common bacterial infections requires growing cultures in a laboratory over a period of days, but diagnosis could be greatly speeded by a number of new sensors based on various nanomaterials that are being developed for ultrasensitive, rapid DNA detection. The new instrument would take from 15 minutes to two hours for a diagnosis and could be used in doctor’s offices, hospitals, and homes.
Each sensor is a hairpin-shaped strand of DNA, complementary to the genetic sequence being targeted, that is fixed on a gold film. Gold quenches the glow of a fluorescent molecule attached to one end of the DNA. The DNA stays folded over until a target genetic sequence links to it. Its unfolding results in the fluorescent molecule moving away from the gold film and glowing, which can be seen under a fluorescent microscope.
Glowing DNA: A CCD camera sensor captures the glow of hairpin-shaped DNA nanosensors when they bind with a target gene sequence of anthrax bacteria. Credit: Benjamin Miller, University of Rochester Medical Center
Lighthouse Biosciences in West Henrietta, NY, is commercializing disposable cartridges to be used with the nanosensor technology. A blood or urine sample to be tested would be placed directly on the cartridge. The cartridge will be a lab-on-a-chip, with rapid, miniaturized ways to prepare the sample for testing. “In the cartridge there are steps for cleaning up samples, that is, extracting material you’re interested in and amplifying the [bacterial] DNA,” Miller says. The cartridge will then be placed in a small portable instrument that does the fluorescence imaging and analysis. Each cartridge should cost a few dollars, Miller says.
By attaching different DNA strands on the gold film, the same cartridge could screen for multiple pathogens, Miller says. So far, the researchers have made a sensor to detect antibiotic-resistant staph bacteria that cause skin infections. They are now working on detecting bacteria responsible for common urinary-tract infections. The sensors could also be used to quickly spot bacteria in food or bioterror agents in water supplies, or even to screen for genetic disorders or cancer.
In a newer version of the sensor, Miller and colleagues stick DNA strands on silver nanoparticles. The silver nanoparticles make the fluorescent signal 10 times brighter. Plus, because thin layers of silver nanoparticles are transparent, the sensor could be coated on glass and optical fibers to make new types of detecting instruments, Miller says.
Eaton Introduces View Series™ Photoelectric Sensors
March 25, 2009 by R. Nelson Parrish
Filed under Photoelectric
PITTSBURGH, PA - Eaton Corporation announces it is introducing the View Series™ of photoelectric sensors, comprised of the new IntelliViewTM and NanoViewTM product families. The View Series sensors expands Eaton’s photoelectric sensor capabilities with new models designed for a variety of challenging industrial applications. The IntelliView sensors are a family of compact, high-performance specialty photoelectric sensors aimed at the needs of packaging, material handling, and other machinery original equipment manufacturers (OEMs). The NanoView sensors are a family of sub-miniature rectangular photoelectric sensors designed for applications and industries where optical performance is important but smaller, less expensive sensors are required.
Models in the IntelliView product family detect grayscale, color and ultraviolet (UV) luminescent registration marks on product and packaging labels. Background and foreground suppression models allow for precision sensing over extended ranges to meet the needs of a wide variety of machinery OEM applications. Other models are capable of reliably measuring a target’s distance and providing an analog output to a control system.
The IntelliView family features:
The View Series of sensors also includes the NanoView family. These sub-miniature sensors are well suited for applications in packaging, material handling, food and beverage, and pharmaceutical industries where space is limited. Despite their small size, NanoView sensors are robust, powerful, highly reliable, and fit advanced optical performance into a tiny package.
The Nanoview family includes:
fixed-focus diffuse; a 20 foot thru-beam; and a 2.6 foot clear object detector.
The NanoView family also includes specialty sensors capable of solving difficult application challenges. These include a fixed-focus diffuse sensor, able to accurately sense targets with precision at its rated focal point of 3.9 inches; a clear object detector model capable of sensing clear objects such as plastic or glass bottles, films, sheets, and packing materials; and thru-beam mode sensors with a narrow beam option, able to detect small targets with high accuracy.
