doi:10.1038/nindia.2016.51 Published online 21 April 2016
Researchers have synthesized a biosensor that can efficiently detect cholesterol in serum samples1. Since abnormally high levels of serum cholesterol are linked to heart diseases, this biosensor is potentially useful for diagnosing heart disorders.
Cholesterol is an essential structural component of nerve cells and plasma membranes, but it can trigger heart disease by clogging arteries. Current techniques for detecting cholesterol are tedious and complex.
To devise an efficient and simple biosensor for detecting cholesterol, the researchers synthesized a nanocomposite consisting of gold nanostrutcures and thiol-modified graphene deposited on a graphite electrode. They then smeared cholesterol oxidase enzyme on this modified electrode.
When exposed to solutions with different cholesterol concentrations, peak current of the biosensor gradually increased. The peak current increased as the pH of the solutions containing cholesterol increased up to pH 7 and gradually decreased as the pH increased from 7 to 10.
When the temperature was increased to 80 degrees Celsius, the current increased and the enzyme on the biosensor showed optimal catalytic activity at this temperature.
The biosensor selectively detected cholesterol even in the presence of interfering agents usually found in clinical serum samples, and it retained its sensitivity for up to 6 weeks, making it suitable for detecting cholesterol in clinical set-ups, the researchers say.
1. Nandini, S. et al. Synthesis of one-dimensional gold nanostructures and the electrochemical application of the nanohybrid containing functionalized graphene oxide for cholesterol biosensing. Bioelectrochemistry 110, 79–90 (2016)