Indian researchers have designed a blood filter using a conducting polymer, polyaniline, that can detect small traces of a protein that is linked to heart disease.
The protein, troponin, and its three regulatory proteins – troponin C, troponin I and troponin T – is integral to the contraction of skeletal and cardiac muscle, reports Nature. For example, troponin I is highly specific for cardiac muscle necrosis. Although the usefulness as a diagnostic marker for various heart disorders is well known, until now there are no reliable tests for measuring the level of troponin in the blood.
The researchers wanted to produce a biosensor using an easy and cost-effective technique. They coated filter papers with the polymer polyaniline, using screen printing and electrochemical deposition. They spread troponin I antibodies on the polymer-coated filter papers, which bound to the paper through covalent bonds.
Then, they conducted electrochemical studies to measure the efficacy of the resulting biosensor. The researchers wrote about the technique in the July 2012 issue of the journal, Electrochemistry Communications.
The result of the technique was that it could selectively detect troponin I through electrochemical transduction. Strips of the polymer-coated paper were used to detect troponin across a wide physiological range (1-100 ng ML-1) with great sensitivity, the researchers write. They believe that the electrochemically coated conducting-based biosensor could form the basis for a point-of-care diagnostic kit for heart disorders.
Source: “Polymer Paper to Detect Heart Disease,” Nature, 6/22/12
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