Graphene-based arsenic sensor
doi:10.1038/nindia.2011.179 Published online 7 December 2011
Researchers have designed a new sensor that could be used for detecting trace levels of arsenic in drinking water and environmental samples. The researchers constructed their sensor by modifying the surface of a glassy carbon electrode with a composite of reduced graphene oxide and lead oxide.
Arsenic is a toxic metalloid that causes skin lesions, lung and bladder cancers. A sophisticated sensor is therefore needed to monitor arsenic levels in water used for drinking and agricultural purposes. Most of today's arsenic sensors are made of silver, platinum or gold, which are expensive. Carbon-based materials, in contrast, are cheaper and have better electrochemical properties. So far, however, researchers have no investigated the potential of carbon-based materials such as graphene oxide (and its modified forms) for detecting arsenic.
The researchers modified the surface of a glassy carbon electrode with reduced graphene oxide and then dipped the modified electrode in a solution containing lead and arsenic, which formed a composite layer of reduced graphene oxide and lead oxide on the electrode surface.
The team observed a measurable current associated with a positive potential. The sensor was able to detect arsenic and lead simultaneously. This study therefore opens up the possibility for simultaneously detecting arsenic and other metal ions.
"The technique is relatively simple compared with other spectroscopic techniques used for arsenic analysis," says lead researcher Sampath Srinivasan. "Given the high surface area and adsorption capacity of graphene-oxide-based materials, we are trying to devise sensor that can simultaneously detect and remove arsenic," he concludes.
- Ramesha, G. K. et al. In-situ formation of graphene–lead oxide composite and its use in trace arsenic detection. Sensor. Actuator. B. Chem. 160, 306-311 (2011) | Article |