What's New in Biosensors

Plenty of engineering work is inspired by nature, and some of it—biosensor development, for instance—actually incorporates biological components. In one example, the cities of New York and San Francisco have installed Intelligent Automation Corp.'s IAC 1090 Intelligent Aquatic BioMonitoring System, which uses fish to continuously monitor public water supplies for contamination and potential terrorism incidents. As the fish swim, breathe, and cough (yes, fish cough!) noncontact sensors monitor parameters such as ventilation and cough rates. Should the fish detect toxic conditions, the IAC 1090 takes a series of water samples and notifies staff. According to IAC, "Chemical concentrations can be measured with an instrument, but only biosensors (fish) can be used to measure toxicity that is potentially harmful to humans." (www.sensorsmag.com/1006/SCbio1~)

Microscale Developments

Chitosan, a structural element found in the exoskeletons of Chesapeake Bay blue crabs, is key to a system that University of Maryland researchers are developing. The researchers use it to coat miniature vibrating cantilevers within a MEMS device. Different cantilevers can detect different substances, and when even a tiny amount of a targeted substance enters the device from the air or water, the chitosan reacts, changing the vibration on the corresponding cantilever. An optical sensing system detects the change and signals the presence of the substance. (www.sensorsmag.com/1006/SCbio2~)

NanoSensors Inc. is evaluating a generic biosensor design that will accommodate a sensor on a chip. According to CEO Dr. Ted Wong, "The company believes in the value of using porous silicon as a sensor substrate to vastly improve the sensitivity for the detection of targeted agents, and now with the [Michigan State University] license, the company will be able to build its first sensors using this platform." Wong is referring to NanoSensors' agreement with MSU that gives it exclusive worldwide rights to use patent-pending electrochemical DNA biosensors for detecting certain bacteria in commercial applications. (www.sensorsmag.com/1006/SCbio3~, www.sensorsmag.com/1006/SCbio4~)

Luminex Corp. has received a $300,000 DARPA research grant that focuses on developing the company's xMAP chip-scale technology for biodefense applications. The concept leverages xMAP—a bead-based flow cytometry solution for multiplexing biological assays—to detect biopathogens on the scale of a microchip. (www.sensorsmag.com/1006/SCbio5~)