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This work investigated changes in the biochemical parameters of multilayer membrane structures, emerging at their modification with multiwalled carbon nanotubes (MWCNTs). The structures were represented by polyelectrolyte microcapsules (PMCs) containing glucose oxidase (GOx). PMCs were made using sodium polystyrene sulfonate (polyanion) and poly(allylamine hydrochloride) (polycation). Three compositions were considered: with MWCNTs incorporated between polyelectrolyte layers; with MWCNTs inserted into the hollow of the microcapsule; and with MWCNTs incorporated simultaneously into the hollow and between polyelectrolyte layers. The impedance spectra showed modifications using MWCNTs to cause a significant decrease in the PMC active resistance from 2560 to 25 kOhm. The cyclic current–voltage curves featured a current rise at modifications of multilayer MWCNT structures. A PMC-based composition was the basis of a receptor element of an amperometric biosensor. The sensitivity of glucose detection by the biosensor was 0.30 and 0.05 μA/mM for PMCs/MWCNTs/GOx and PMCs/GOx compositions, respectively. The biosensor was insensitive to the presence of ethanol or citric acid in the sample. Polyelectrolyte microcapsules based on a multilayer membrane incorporating the enzyme and MWCNTs can be efficient in developing biosensors and microbial fuel cells.

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Microbial fuel cells (MFCs) are a variety of bioelectrocatalytic devices that utilize the metabolism of microorganisms to generate electric energy from organic matter. This study investigates the possibility of using a novel PEDOT:PSS/graphene/Nafion composite in combination with acetic acid bacteria Gluconobacter oxydans to create a pure culture MFC capable of effective municipal wastewater treatment. The developed MFC was shown to maintain its activity for at least three weeks. The level of COD in municipal wastewater treatment was reduced by 32%; the generated power was up to 81 mW/m2 with a Coulomb efficiency of 40%. Combining the MFC with a DC/DC boost converter increased the voltage generated by two series-connected MFCs from 0.55 mV to 3.2 V. A maximum efficiency was achieved on day 8 of MFC operation and was maintained for a week; capacitors of 6800 µF capacity were fully charged in ~7 min. Thus, G. oxydans cells can become an important part of microbial consortia in MFCs used for treatment of wastewaters with reduced pH.

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Integration of nanostructures with acoustic delay lines within planar technologies give the chance of development the acoustonanoelectronic sensors with high sensitivity and selectivity. An initial step in this direction is investigation of interaction of tunnel nanostructures with acoustic piezoactive waves propagating in piezoelectric substrates. In this work the technology of nanowire production on the surface of lithium niobate plate has been developed. This technology is based on using electronic lithography method with help an electronic beam in a raster electronic microscope. The nanostructure consisting of nanowire with size 20nm x 180nm was placed in the center between IDTs of acoustic delay line. The volt-ampere characteristics of this nanowire in presence and at the absence of the acoustic wave were meazured by picoampermeter. The analysis has shown that presence of piezoactive acoustic wave is influenced on electric current in a nanowire.

Graphene oxide (GO) possesses some unique properties, which allow its technological applications in many fields (energy storage, microelectronic devices, and chemical sensors). It can also be used as a sensitive layer in the development of the chemical acoustoelectronic sensors. We characterized the produced GO films by measuring their structural properties, permittivity, and longitudinal/shear elastic moduli. For the first time, we determined the longitudinal and shear elastic moduli of a GO film under study to be 12.3 ± 0.1 MPa and 3.0 ± 0.1 MPa, respectively. The density of the GO film is equal to ∼850 kg m−3. The permittivity of the GO film was found to be 21 for a frequency f = 20 Hz. The obtained results may be used in further application of GO films in acoustoelectronic sensor devices.

In this research, beam focusing in lithium niobate plate was studied for fundamental anti-symmetric (A0) and symmetric (S0) Lamb waves, and the shear-horizontal (SH0) wave of zero-order. Using the finite element method, appropriate configuration of the interdigital transducer with arc-like electrodes was modeled accounting for the anisotropy of the slowness curves and dispersion of the modes in the plate. Profiles of the focalized acoustic beams generated by the proposed transducer were theoretically analyzed. Based on the result of the analysis, relevant delay lines were fabricated and transfer functions (insertion loss) of the line were measured for SH0 wave in YX-lithium niobate plate. Using an electron scanning microscope, distribution of the electric fields of the same wave were visualized. The results of this study may be useful for hybrid devices and sensors combining nano and acoustoelectronic principles.