New 'Nanobead' Approach Could Revolutionize Sensor Technology

Researchers at Oregon State University have found a way to use magnetic "nanobeads" to help detect chemical and biological agents, with possible applications in everything from bioterrorism to medical diagnostics, environmental monitoring or even water and food safety. When fully developed as a hand-held, portable sensor, like something you might see in a science fiction movie, it will provide a whole diagnostic laboratory on a single chip.

The research could revolutionize the size, speed and accuracy of chemical detection systems around the world.

New findings on this "microfluidic sensor" were recently reported in Sensors and Actuators, a professional journal, and the university is pursuing a patent on related technologies. The collaborative studies were led by Vincent Remcho, an OSU professor of chemistry, and Pallavi Dhagat, an assistant professor in the OSU School of Electrical Engineering and Computer Science.

The key, scientists say, is tapping into the capability of ferromagnetic iron oxide nanoparticles –extraordinarily tiny pieces of rust. The use of such particles in the new system can not only detect chemicals with sensitivity and selectivity, but they can be incorporated into a system of integrated circuits to instantly display the findings.

"The particles we're using are 1,000 times smaller than those now being used in common diagnostic tests, allowing a device to be portable and used in the field," said Remcho, who is also associate dean for research and graduate programs in the OSU College of Science.

"Just as important, however, is that these nanoparticles are made of iron," he said. "Because of that, we can use magnetism and electronics to make them also function as a signaling device, to give us immediate access to the information available."

According to Dhagat, this should result in a powerful sensing technology that is fast, accurate, inexpensive, mass-producible, and small enough to hold in your hand.