20.500.12556/DKUM-98660 Določanje minimalne inhibitorne koncentracije vanilina proti saccharomyces cerevisiae z impedančnim biosenzorjem Determination of the minimum inhibitory concentration of vanillin against saccharomyces cerevisiae with an impedance biosensor V diplomskem delu smo z impedančnim biosenzorjem določali minimalno inhibitorno koncentracijo vanilina proti kvasovkam vrste Saccharomyces cerevisiae. Namen dela je bil dokazati, da so spremembe impedance neposredno povezane z učinkom vanilina na celice, s čimer bi EIS lahko predstavljala hitrejšo in učinkovitejšo metodo kot klasična metoda, spremljanje rasti z merjenjem optične gostote pri valovni dolžini 600 nm (OD600). V eksperimentalnem delu smo pripravili elektrokemijsko celico iz nerjavnega jekla tipa SS316 v RCW side-by-side konfiguraciji in na delovno elektrodo nanesli celice kvasovk vrste Saccharomyces cerevisiae. Meritve smo izvajali pri različnih koncentracijah vanilina, rezultate pa predstavili z Nyquistovim in Bodejevim diagramom. Padanje impedance sistema z naraščanjem koncentracije vanilina smo prikazali tudi z umeritveno krivuljo in stolpčnim diagramom ter določili mejo detekcije (LOD) in mejo določljivosti(LOQ). Izvedli pa smo tudi spremljanje rasti kvasovk z merjenjem optične gostote pri valovni dolžini 600 nm (OD600). Za obe metodi smo izračunali vrednosti EC10, EC20 in EC50 ter jih med seboj primerjali. Rezultati so pokazali, da se z naraščanjem koncentracije vanilina zmanjšujeta fazni kot in absolutna vrednost impedance, kar nakazuje na inhibitorni učinek vanilina na kvasovke Saccharomyces cerevisiae. Primerjava vrednosti EC10,EC20 in EC50, dobljenih z metodo EIS in spremljanjem rastnih krivulj, je pokazala da metoda EIS zazna vpliv vanilina pri koncentracijah višjih od 1,5 mM. Ugotovili smo, da naš biosenzor predstavlja občutljivejšo metodo od spremljanja rastnih krivulj ter predstavlja obetavno tehniko za določanje minimalne inhibitorne koncentracije vanilina. In this study, we determined the minimum inhibitory concentration of vanillin against Saccharomyces cerevisiae yeast using an impedance biosensor. The purpose of this work was to demonstrate that changes in impedance parameters are directly related to vanillin's effect on cells, suggesting that EIS could be a faster, more efficient method than the classical approach of monitoring cellular growth by measuring optical density at 600 nm (OD600). In the experimental part, we prepared an electrochemical cell made of SS316 stainless steel in an RCW side-by-side configuration and applied Saccharomyces cerevisiae yeast cells to the working electrode. Measurements were performed at various vanillin concentrations, and the results were presented using Nyquist and Bode plots. The decrease in the system's impedance with increasing vanillin concentration was also illustrated with a calibration curve and a bar chart, and the limit of detection (LOD) and limit of quantification (LOQ) were determined. Additionally, we monitored yeast growth by measuring optical density at 600 nm (OD600). For both methods, we calculated the EC10, EC20, and EC50 values and compared them. The results showed that as the vanillin concentration increases, the phase angle and absolute impedance decrease, indicating an inhibitory effect of vanillin on Saccharomyces cerevisiae. A comparison of the EC10, EC20, and EC50 values obtained using the EIS method and by monitoring growth curves showed that the EIS method detects the impact of vanillin at concentrations above 1,5 mM. We concluded that our biosensor is more sensitive than growth curve monitoring and represents a promising method for determining the minimum inhibitory concentration of vanillin. vanilin kvasovke vrste Saccharomyces cerevisiae elektrokemijska impedančna spektroskopija impedančni biosenzor minimalna inhibitorna koncentracija rastna krivulja vanillin Saccharomyces cerevisiae yeast electrochemical impedance spectroscopy impedance biosensor minimum inhibitory concentration growth curve true true false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-06-29 16:33:05 2026-09-04 13:57:03 2026-09-05 03:09:29 0000-00-00 00:00:00 2026 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 VS_Kalik_Barbara_2026.pdf VS_Kalik_Barbara_2026.pdf 1 D3E8407ACA4AFA630A8A27594545B780 ce59c1cdcf40a6a99591d1bc1b2e0107494e6585677ba27b73904c80e050c29b ee663c57-9aef-11f1-8356-00155d0001be https://dk.um.si/Dokument.php?lang=slv&id=209745 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0