INVESTIGATION OF A HETEROGENEOUS ADSORPTION LAYER ON AN ENERGETICALLY INHOMOGENEOUS SURFACE BIOLOGICAL AND SEMICONDUCTOR SENSORS
The features of the formation of adsorption layers on the energetically inhomogeneous surface of biological membranes or porous semiconductor crystals are considered. It is shown that the initially hydrophobic surface of the sensor acquires hydrophilic properties due to the active centers having different physical nature on the plasmalemma and the porous crystal. A heterogeneous adsorption layer is formed on the surface of the sensors: a coordination-saturated film and a two-dimensional gas of molecules performing translational diffusion. The fractal structure of the coordination-saturated layer is formed as a result of the breaking of hydrogen bonds on the isoenergetic line separating neighboring clusters. An increase in the concentration of active centers on the sensor surface contributes to the formation of a fractal network of isoenergetic lines, which can serve as a proton conduction zone for dissociated protons. Adsorption processes on both structures are isomorphic in the sensor sensitivity region and occur as a phase transition in a heterogeneous structure under isobaric-isothermal conditions of surface pressure. It is shown that fractal structures formed on the surface of sensors have memory, while the memory of a semiconductor sensor is generated under processing conditions, while the memory of a biological sensor is formed as a reaction to external impacts.
Authors: A. I. Mamykin, M. N. Shishkina
Keywords: Adsorption, biological sensor, porous crystal, energetically inhomogeneous surface, heterogeneous adsorption layer, coordination-saturated film, two-dimensional translational diffusion gas
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