doi:10.1038/nindia.2014.10 Published online 24 January 2014
Researchers have fabricated a biosensor from gold-coated zinc oxide nanorods that can detect varying concentrations of glucose, a vital molecule found in human blood1 . This sensor is nontoxic and can be used for continuous monitoring of glucose in biological samples.
The researchers fabricated the highly sensitive biosensor by coating zinc oxide nanorods with gold. They smeared the biosensor with the fungal enzyme glucose oxidase. They measured the efficacy of this gold-coated biosensor in sensing varying concentrations of glucose and compared it with that of a biosensor made from uncoated zinc oxide nanorods.
In electrochemical measurements, the gold-coated biosensor exhibited a higher oxidation current than the uncoated biosensor when exposed to glucose solutions. This indicates that the gold coating contributed to the better response of the gold-coated biosensor. It reached a steady-state current in less than 5 seconds.
The gold-coated biosensor exhibited a linear response over a wider range of glucose concentrations than the uncoated biosensor. The gold-coated biosensor transferred charge efficiently. To enable electrochemical sensing to be done using a chip, the biosensor will be miniaturized using microfabrication techniques.
'This biosensor can be designed to act as multiarray sensor containing tiny chambers for detecting different molecules besides glucose," says Sangam Banerjee, a senior author of the study.