Surface modification of wearable microneedle-based biosensor systems

To serve the increasing demand for low-cost and easy-to-use point-of-care (POC) diagnostic systems for healthcare and lifestyle, upscaling of the underlying biosensor system concepts using novel functionalization strategies for sample preparation or signal generation is crucial. The Molecular Diagnostics competence unit of the AIT Austrian Institute of Technology GmbH addresses this need by investigating key research issues for low-volume (picoliter/nanoliter) inkjet printing or “high volume” spotting techniques (microliter), and therefore, works on the development of printing processes and (bio)inks for reproducible batch production, e.g., for functional (bio)sensors, immuno- or enzymatic assays, as well as nucleic acid diagnostic devices. In this presentation, we will review results related to these aspects from the ELSAH project (H2020, No 825549). ELSAH aims at the realization of a wearable, microneedle-based biosensor system for the continuous monitoring of glucose and lactate in the interstitial fluid for lifestyle diagnostics. Formulated bioinks comprise direct electron transfer (DET) enzymes containing PEDOT:PSS inks (PEDET ink) and hydrogel precursors inks. The developed spotting techniques allow local deposition of glucose- or lactate-sensitive PEDET inks and hydrogel protection layers on microneedle-based amperometric sensors.