Detecting heart failure by saliva analysis was made possible in Russia
Russian and Serbian scientists have developed a device for relatively rapid detection of heart failure by analyzing the patient's saliva, the Russian Scientific Foundation told RIA Novosti. Cardiovascular diseases remain the leading cause of death in the world. To assess the risk of these ailments, a blood test is usually needed. One of the markers of heart failure can be the protein NT-proBNP, which is released in large quantities under strong stresses (sprains) in myocardial cells and actively enters the blood. A test for this protein has already entered clinical practice, but sometimes blood sampling for analysis can be harmful for a patient — for example, if he is in the intensive care unit and has a large blood loss.
The marker can also be determined by analyzing saliva. But the concentration of NT-proBNP in human saliva is a thousand times lower than in blood, which means that highly sensitive devices to accurately measure its amount are needed.
Scientists from MIET and the Institute for Research and Development of Information Technologies in Biosystems (Serbia) have developed a highly sensitive sensor based on graphene, a material with only one layer of carbon atoms. Graphene served as a conductor, i.e. an element that conducts electric current differently depending on whether there is an NT-proBNP protein in the analyzed solution. To make the sensor more susceptible to the protein, the scientists attached a molecule that is a receptor to graphene and can be compared with the tongue receptors capable of recognizing substances responsible for a particular taste. As a result, the electron concentration changed in the presence of the NT-proBNP protein in the graphene conductor. It was used to track the marker of heart failure.
Scientists needed only two characteristics of the device: conductivity and threshold voltage. Conductivity is the ability of substances to conduct current and is associated with the presence of charge carriers in them. The higher the protein concentration, the more electrons the sample carried. The threshold voltage is inversely proportional to the electron concentration: if the number of charged particles increased, the voltage dropped. Thus, if these parameters are measured concurrently, the reliability of the analysis increases.
The researchers tested the sensor on artificial saliva. Chemical composition of which is similar to real saliva, but more indicative, since its properties are easier to control. As a result, the sensor detected the NT-proBNP marker in less than ten minutes. Such blood serum tests take much longer, about 45 minutes. According to the researchers, in the future this test can be used in emergency wards when it is necessary to quickly identify possible causes of deterioration of someone's condition.
Source: RIA Novosti