Silver News

Nano-Silver Used in Super Sensor

Silver nanoparticles have unique optical properties, especially enhanced sensitivity to changes in their environment, and show promise as sensors used in applications ranging from laboratory testing equipment to biohazard alarms.

When light is reflected off a substance, it scatters into many different wavelengths, depending upon the material’s unique chemical make-up.

Scientists at Tennessee’s Oak Ridge National Laboratory led by Dr. Tuan Vo-Dinh have built a silver nanoprobe based on these light scattering techniques. Tuan says that the probe can detect and analyze chemicals, explosives, drugs, and other substances of close to a single molecule size. This ability makes it possible to detect minute amounts of substances despite the environment.

The probe is a 100 nanometer optical fiber honed to a point with an extremely thin coating of silver nanoparticles that are sensitive to light. When a laser is pointed at the sample, light is reflected and scattered according to a pattern unique to that substance. This pattern is captured by the probe and fed into a computer for analysis.

Research continues to produce a sensor that can be used outside the laboratory, but the team says it’s just a matter a time before this is accomplished.

Silver News - Fourth Quarter 2004