At the Biosensing and Bioanalysis Group of the Universitat Autònoma de Barcelona, we are developing new diagnostic strategies to detect Alzheimer’s disease at earlier stages, before neuronal damage becomes extensive.
In our recent study, we present a liquid-biopsy approach based on plasma exosomes: small extracellular vesicles that circulate in the bloodstream and carry molecular information from their cells of origin. These vesicles are especially interesting because they may provide access to biological information related to the brain through a minimally invasive blood sample.
The main challenge is that plasma contains exosomes released by many different tissues. For this reason, our strategy first focuses on selectively enriching brain-derived exosomes. We do this using magnetic particles functionalized with an antibody against neuroligin-3 (NLGN3), a protein associated with brain synapses. This magnetic selection step allows us to isolate an exosome fraction carrying signals consistent with neuronal origin.
Once this enriched fraction is obtained, we use a portable electrochemical biosensor to quantify beta-secretase 1 (BACE-1), an enzyme involved in biological processes related to amyloid-beta formation, one of the hallmarks of Alzheimer’s disease. The system is based on screen-printed electrodes and single-use cartridges, converting a biochemical reaction into an electrical signal that can be measured with compact and battery-operated equipment.
Our preliminary results are very promising and support the potential of this approach as a future tool for early screening and patient follow-up. We are now expanding the study to larger cohorts to further evaluate its diagnostic performance.
This work represents a step towards accessible, minimally invasive and portable diagnostic technologies for neurodegenerative diseases.
Reference
Rossi, R., Cano, A., Pallarès-Rusiñol, A., Ruiz, A., Martí, M., & Pividori, M. I. (2026). Electrochemical biosensor for early Alzheimer’s detection and patient risk stratification using plasma exosomes. Biosensors and Bioelectronics, 292, 118061. https://doi.org/10.1016/j.bios.2025.118061