New sensor signals heart disease
doi:10.1038/nindia.2012.188 Published online 19 December 2012
Researchers have designed a new kind of nanosensor that can detect minute traces of myoglobin, a muscle protein released into the bloodstream when heart and skeletal muscles are damaged. The sensor will be handy in diagnosing the onset of heart disease and the extent of heart muscle damage by detecting myoglobin in the bloodstream.
Myoglobin is an iron-containing, oxygen-binding protein found in the muscle tissues of vertebrates in general and in almost all mammals. Myoglobin is released in the bloodstream following muscle injury. As a biomarker protein, its abnormal presence in blood can be used for diagnostic purposes. Given the role of the heart as a vital muscular organ continuously pumping out blood to all the organs, it is necessary to monitor the health of heart muscle to predict the threat of impending heart attack following profuse secretion of myoglobin.
To find a simple, effective sensor to detect myoglobin, the researchers coated zinc sulphide nanocrystals with mercaptonoic acid (MPA) and attached these MPA-capped nanocrystals to a self-assembled monolayer of organic compound on an indium tin oxide (ITO)-coated glass plate. They then smeared anti-myoglobin protein antibody on this modified nanosystem-attached glass plate, yielding the nanosensor.
In electrochemical studies, the nanosensor showed increase in resistance after immunoreaction with the antigen myoglobin. The nanosensor could detect levels of antigen myoglobin as low as 10 nanograms per milliliter.
The authors of this work are from: Polymer and Soft Materials Section, CSIR—National Physical Laboratory, New Delhi and Department of Applied Chemistry, Delhi Technological University, Bawana Road, Delhi, India.