One way of diagnosing a heart attack involves detecting increased levels of the protein troponin in a patient’s blood. The equipment necessary to do that tends to be bulky and expensive, preventing its use in poor and remote locations. Korean researchers have now developed a thermometer-like device that can measure the concentration of troponin in human serum.
The device uses platinum nanoparticles that have antibodies on their surface that are attracted to troponin to separate the protein from the blood serum. After hydrogen peroxide is added to capsule with the troponin stuck to the glass walls, it is capped and a transparent tube with a drop of ink is stuck to the top. The pressure within the capsule begins to go up as the hydrogen peroxide breaks down into water and oxygen. The increase in this pressure, which is measured by the distance the ink drop moves up the tube, indicates the amount of platinum nanoparticles, and hence troponin, in the solution.
From the study abstract in Analytical Chemistry:
The sensitivity of this assay for TnI in human serum after a 5 min dissociation reaction, detected with the naked eye, was 0.1 ng/mL, which was better than the sensitivity of the conventional colorimetric method using the TMB oxidation reaction under the same experimental conditions. A control experiment using alpha-fetoprotein, interleukin-5, and C-reactive protein revealed that the developed method was highly selective for the detection of TnI.
Study in Analytical Chemistry: Facile detection of troponin I using dendritic platinum nanoparticles and capillary tube indicators…
Source: American Chemical Society…