A group of scientists, at Lawrence Livermore National Laboratory, has created a nanosensor that uses semiconductor nanowires as a source of energy. The device is easy to use, sensitive and is able to identify multiple molecules rapidly. It will be suitable for use in the defense sector.
Yinmin Morris Wang and Daniel Aberg, Paul Erhart, Nipun Misra, Aleksandr Noy and Alex Hamza from the lab collaborated with a team from the University of Shanghai for Science and Technology to create battery-free sensors deploying one-dimensional semiconductor nanowires.
The device uses communication between chemical communities and the surface of a semiconductor nanowire that trigger an electrical charge to travel between the two nanowire ends or between the exposed and hidden nanowires. The sensors were tested with platforms such as zinc-oxide and silicon. Ethanol solvent was used as a testing agent. A change occurred in the voltage between the nanowire ends in the zinc-oxide sensor when nano-scale ethanol was kept on it.
According to Wang, the electric signal increased immediately, and deteriorated slowly while the ethanol evaporates. Nano-quantities of hexane solvent placed on the detector exhibited little voltage. This showed that the device reacts to multiple kinds of solvent molecules.
Over 15 different kinds of organic solvents were used and exhibited multiple voltages in each solvent. This feature will allow nano-sensors to identify multiple chemical groups and their concentration levels. Silicon nanosensors also exhibited the same characteristics. The voltage decline differed from that of the zinc-oxide sensors. This showed that the device can be applied to haphazardly arranged nanowire systems.
The research paper has been published in a January issue of Advanced Materials.
Source: https://www.llnl.gov