2023-12-19 16:45:16
Invasive aspergillosis is a disease that mainly affects immunosuppressed people. It is caused by a fungus that generates symptoms similar to those of tuberculosis. A UNSL researcher developed a biosensor for early detection.
Chemistry graduate Sofía Piguillem, from the National University of San Luis (UNSL) in Argentina, focused her doctoral studies on the development of a biosensor to detect invasive aspergillosis using galactomannan, a specific component of the fungus that causes the disease.
The disease mainly affects immunosuppressed people. When they contract the disease, the fungus passes from the bloodstream to the organs. The symptoms it presents can be fever, headache and coughing up blood and, on several occasions, it has been diagnosed as tuberculosis, resulting in erroneous treatment of the disease.
“About 30% die without knowing that they have had this disease; The necessary tests have never been done to specifically detect Aspergillus. So, since the person is misdiagnosed, they generally die without knowing that they have had this pathology (…) That is where the need for its detection arises,” the scientist explained to Argentina Investiga.
The doctor in Chemistry expressed that there is a way to detect it, which is through a specialized kit, whose commercialization is foreign and in Argentina it is generally found in laboratories in Buenos Aires. The new sensor, developed at the UNSL Bioanalytical Laboratory, allows sensitive, specific and reliable results to be obtained in less time.
Biosensors are generally small, miniaturized devices. A biosensor has a biorecognition element, that is, an immobilized antibody detects it from the galactomannan molecule. To further improve the properties of the biosensor, the scientist used nanomaterials.
Sofía Piguillem. (Photo: UNSL Institutional Press)
Sensor tuning
As a first measure, all possible nanomaterials were synthesized to apply them to the sensors and thus increase sensitivity and observe which responds best. Other types of nanomaterials called metal-organic frameworks (MOFs) were also synthesized, which have the same purpose: to expand the reaction area.
After carrying out the synthesis work, we studied how to apply the procedures to immobilize the antibody and thus detect the antigen. “We worked using a syringe pumping system; We inject the solutions into the channels of the microfluidic sensor and, as the antigen, the antibody and the substrate pass electrochemically or by fluorescence, we detect the compound,” explained the researcher.
The element that was studied to recognize the disease was human serum, this is a liquid that is obtained after the blood is treated. “If we detect galactomannan there, we could say that the person is suffering from the disease invasive aspergillosis,” Piguillem specified, adding that this pathology has a cure if it is treated in time. With this development, early detection would be made to carry out correct therapy.
Currently there are few publications that address galactomannan as a topic. At the National University of San Luis (UNSL), Sofía Piguillem’s is the only thesis referring to this fungus. Now it is being analyzed whether a further step can be taken, that is, reaching a Laboratory so that it can be widely implemented, since all the samples are transferred to Buenos Aires.
We find the fungus everywhere: in damp walls, in air conditioning filters that are not cleaned, in decomposing plant matter, in foods that are usually contaminated, “we have the fungus around us all the time, the only thing is that People who are immunocompromised, having low defenses, inhale it and, if it is not controlled in time, the disease develops,” said Piguillem.
Sofía Piquillen graduated with a degree in Chemistry in 2016 and recently defended her doctoral thesis. Her professional training led her to train in Madrid (Spain), where she worked on different techniques with biosensors. There she studied an analyte linked to heart disease. (Source: Fabiola Gisel Aranda / National University of San Luis / Argentina Investiga)
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