A novel Bod-mediator biosensor based on Ferrocene and Debaryomyces hansenii yeast cells

The mediators ferrocene, 1,1'-dimethylferrocene, ferrocene carboxaldehyde, ferrocene acetonitrile, neutral red, 2,6-dichlorophenolindophenol, thionine, methyl blue, and potassium ferricyanide were used in combination with Debaryomyces hansenii yeast cells to create a biosensor receptor for biochemical oxygen demand (BOD) assays. In this eukaryote, ferrocene and neutral red were observed to efficiently transfer electrons. The biosensor based on ferrocene was characterized by long-term stability (39 days) and a wide range of substrate specificity. The lower detected concentration boundary was 25.2 mg O2/dm3. A high correlation (R = 0.9971) was observed between the results obtained with water samples by this approach and the standard method. This is the first attempt to create a combination of yeast cells and a mediator. The biosensor can be employed for further research on the possibilities of its conventional use.