Scientists from Brazil and the United Kingdom have worked in partnership to reuse espresso coffee capsules — a material that is rarely recycled nationally. Initially, the waste was used as raw material for 3D printers. Now, these filaments make up a sensor capable of diagnosing yellow fever and distinguishing the infection from dengue cases.
The size of a coin, the electrochemical biosensor has low production costs as it is made from recycled materials. Therefore, it should facilitate diagnosis and can improve access to healthcare in more remote locations, reducing the risk of deaths due to yellow fever — a disease also transmitted by the “dengue mosquito”, the Aedes aegypti
The invention using coffee capsules was recently described in the scientific journal Chemical Engineering Journal . Among those responsible for the proposal is Cristiane Kalinke, post-doctoral student at the Institute of Chemistry at the State University of Campinas (IQ-Unicamp) and visiting researcher at the Metropolitan University of Manchester.
Coffee capsule sensor
The surface of the biosensor has electrodes printed using 3D technology with polylactic acid (PLA), which comes from processed and recycled coffee capsules. Furthermore, carbon and carbon black (fine black powder, derived from the partial burning of oil or natural gas residues) are used as additives, as they guarantee the conductivity of the sensor and generate the chemical reaction necessary for diagnosis.
Sensor made from recycled material from coffee capsules diagnoses yellow fever (Image: Kalinke et al., 2023/Chemical Engineering Journal)
To diagnose yellow fever, simply use a drop of blood serum, that is, around 200 microliters of plasma. So far, it is not possible to directly use a blood or saliva sample, but the idea is to make this viable in the future.
Cheap yellow fever test
“Miniaturized sensors like this could be easily transported to remote regions or communities, where yellow fever is more common”, says researcher Kalinke for the Fapesp Agency
Thus, the invention is built in accordance with the principles established by the World Health Organization (WHO), such as accessibility, good sensitivity and ease of use for these tests aimed at neglected diseases. More importantly, it does not need large equipment to carry out the processing.
Before reaching the market, researchers will still carry out additional tests and, ideally, allow simpler samples from patients to be used. However, expectations are already high.
It is worth noting that the research project, funded by Fapesp, also had the support of scientists from the Federal University of São Carlos (Ufscar) and the University of São Paulo (USP).
Source: Chemical Engineering Journal and Agência Fapesp