Maksimchuk N. Cerium oxide films for biosensors of toxic substances

Through changing the microstructure and morphology of the films we have determined the main principles of control of their physical properties. We established the technological conditions which allow obtaining nanocrystalline СеОх-films with desired functional characteristics for the creation of effective biosensors for the detection of toxic substances. On the basis of synthesized nanocrystalline СеОх-films obtained by the "explosive evaporation" method we developed new types of photodetectors for registration of bioluminescent signal (photoresistors and photodiodes) with increased photosensitivity (310-330 mA/lm·V). Such photodetectors turned out to be free of deficiencies of photomultiplier tubes and avalanche photodiodes. Within the potentiometric biosensory transducers (ion-selective field-effect transistors) the use of dielectric СеОх-films obtained by "metallic mirrors oxidation" method proved to yield higher sensitivity and stability as compared to the use of the SiO2 and Si3N4 films. Photoresistors and MOS-photodiodes with СеОх-films allowed us to create a new type of bioluminescent sensor based on the effective semiconductor photodetectors for determining the concentration of toxic substances. Application of semiconductor photoresistors instead of photomultiplier tubes and avalanche photodiodes allows to significantly decrease the cost of bioluminometer and increase its sensitivity when measuring at alternating signal.