The researchers at Indian Institute of Technology, Hyderabad (IIT-H), have collaborated with research institutions across the world to develop a device to detect heart diseases in minutes. In a work published recently in the peer-reviewed Journal of Materials Chemistry B , they say their work not only promises diagnosis or prediction of heart disorders within minutes, but can also be extended to detection of other diseases.
Headed by Renu John, head of Department of Biomedical Engineering, IIT-H, the research team says clinical complications of cardiovascular diseases (CVD) are at present the major causes of morbidity and mortality worldwide.
Primary and specialist health-providers use a variety of tools for clinical assessment of the existing heart diseases and to identify vulnerable patients at risk for CVD. Biosensors are one such tools. Prof. Renu John’s studies on microfluidics would help in building biomarker-based biosensors that could be used for instantaneous detection of heart attack and other cardiac diseases.
“Biomarkers are biological molecules that represent health and disease states. They are specific chemicals that are released in the body in response to certain physiological conditions. Cardiac troponins or cTns, for instance, are biomarkers of heart diseases and are conventionally detected in the blood stream using antibodies that bind specifically to them. Biosensors are devices that combine the sensing element (the antibody) with a transducer that converts the interaction of antibody into electrical or optical signal that can be measured. Conventional biosensing includes such techniques as ELISA, chemiluminescent immunoassay and radioimmunoassay,” said Prof. Renu John.
B.D. Malhotra from Delhi Technological University said, “The major issue with the conventional assays for the detection of cTns relates to poor sensitivity and limitations in detection. Improvements in detecting biosensors such as cTns in blood require improvements in the design of the biosensor”.
Prof. Malhotra believes that the technique can be extended to other diseases as well by varying the type of biomarker/antibody that is attached to the nanospheres. Thus, microfluidics-based biosensing offers new opportunities in the areas of biological engineering, biomedical studies, point-of-care diagnostics, and environmental monitoring.
Prof. Renu John’s team and collaborators from IIT-Kanpur, Zoological Survey of India, Iowa State University and Delhi Technological University, used hollow nickel vanadate nanospheres, modified with chitosan and loaded with antibodies of cTns in a microfluidic set-up. When blood containing the CVD biomarker cTns passed through the biofluidic set-up loaded with biosensing nanospheres, cTns binds with the antibody and induces an electrical signal in the nanosphere, which is then detected.
Prof. Renu John and his team tested the performance of the microfluidic biosensors using blood serum of cardiac patients and compared the results with those of conventional chemiluminescence assays.
They found that the microfluidic devices could detect the CVD biomarker cTns with extremely high degree of accuracy and sensitivity. cTns levels as low as 0.000000000005 grams in one millilitre of blood could be detected, which makes this technique a useful tool for detection of cardiovascular maladies, they say.
