doi:10.1038/nindia.2014.106 Published online 12 August 2014
Researchers have fabricated an ecofriendly biosensor that can detect minute traces of hydrogen peroxide, a chemical harmful to human health1. This biosensor is potentially useful for measuring hydrogen peroxide levels in biological and environmental samples.
Hydrogen peroxide is a strong oxidizing agent and, as such, it is used in aqueous solutions as a ripening agent, a bleaching agent and a disinfectant. However, at high concentrations, it can induce abdominal pain and swelling and damage to the lungs and eyes.
To develop a biosensor for rapidly detecting hydrogen peroxide, the researchers used the bark extract of a medicinal plant to synthesize silver nanoparticles. They then prepared a biocomposite by mixing these nanoparticles with myoglobin, an oxygen-binding protein found in the heart and muscles. Finally, they fabricated the biosensor by using this biocomposite to modify an electrode.
The researchers evaluated the efficacy of the biosensor in measuring the hydrogen peroxide concentrations of aqueous solutions. They found that the biosensor could detect hydrogen peroxide within 5 seconds. They attribute this rapid sensing to fast electron transfer by the myoglobin in the biocomposite used to modify the electrode.
This result indicates that fast electron transfer by the myoglobin contributed to the catalytic activity of the biosensor. The biosensor exhibited a linear response over the wide range of 1 micromole to 3 millimoles and could detect hydrogen peroxide concentrations down to 0.088 micromoles. The researchers say that the biosensor showed an excellent precision and good consistency in sensing hydrogen peroxide.