20.500.12556/DKUM-98509 Rapid eukaryotic impedimetric biosensing of naproxen and isoniazid a proof-of-concept for acute toxicity monitoring This study presents a rapid, eukaryotic impedimetric biosensor that applies the yeast Saccharomyces cerevisiae as a robust, cost-effective biorecognition element for monitoring the acute toxicity of two representative pharmaceuticals, naproxen and isoniazid, in aquatic systems. The biosensor utilizes a previously developed three-electrode system made from type 316 stainless steel. Yeast cells seeded onto these electrodes serve as the biosensing element. By monitoring changes in electrical impedance, the system quantifies the cellular stress induced by pharmaceutical exposure. Electrochemical Impedance Spectroscopy (EIS) revealed a concentration-dependent decrease in both resistance and capacitance, attributed to cell death and subsequent desorption from the working electrode surface. These findings were validated through optical density at 600 nm (OD600) growth curve analysis and methylene blue viability staining, which confirmed metabolic inhibition and membrane damage. Results indicate a linear response for naproxen within the 2.5 mM to 20 mM range, with a LOD of 0.509 mM, and for isoniazid within the 10 mM to 100 mM range, with a LOD of 0.684 mM. Naproxen demonstrated a more pronounced cytotoxic effect, with cell viability dropping to 41.08% at 10 mM compared to 68.79% for isoniazid. While conventional analytical methods focus on chemical quantification, this proof-of-concept biosensor provides a rapid toxic/non-toxic signal, offering a biologically relevant tool for real-time monitoring of industrial waste streams and acute environmental contamination. acute toxicity monitoring impedimetric biosensor Saccharomyces cerevisiae electrochemical impedance spectroscopy EIS pharmaceutically active compounds naproxen isoniazid biosenzorji elektrokemija spektroskopija true false true MDPI Angleški jezik Slovenski jezik https://www.mdpi.com/journal/biosensors Članek v reviji 2026-06-17 15:10:47 2026-06-17 15:10:47 2026-06-30 14:59:20 0000-00-00 00:00:00 2026 0 0 17 str. št. 5, št. članka 298 Letn. 16 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2026-04-08 2025-05-18 2026-05-20 544 278962435 10.3390/bios16050298 2079-6374 Rapid_Eukaryotic_Impedimetric_B-Stukovnik-2026.pdf Rapid_Eukaryotic_Impedimetric_B-Stukovnik-2026.pdf 1 00C4AFDF4A9E630A4DA6540F3A306AD9 b4b73504b12a9ab5594bcd888fc4ae0916daaf84f7ec09f04c9ff7c46ab5a757 74d4ff09-6a4f-11f1-87c9-00155d580e34 https://dk.um.si/Dokument.php?lang=slv&id=207250 https://www.mdpi.com/2079-6374/16/5/298 0 1fa8aa53-7483-11f1-904a-00155d580e34 https://dk.um.si/Dokument.php?lang=slv&id=207730 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0