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We studied methods of the in situ synthesis of gold nanostructures on the electrode surface and of the directed electrochemical synthesis of nanodendrites to create biosensors based on horseradish peroxidase. The effect of nanostructuring of the transducer surface and its subsequent modification on the electroanalytical characteristics of sensors for the determination of hydrogen peroxide was studied. The use of these methods can significantly improve the performance characteristics of the biosensors, such as the sensitivity coefficient, limit of detection, and stability in the range of micromolar and submicromolar concentrations of hydrogen peroxide. The electrodes modified by the in situ synthesis of nanostructures with subsequent treatment with Meerwein's reagent, as well as ultramicroelectrodes prepared by directional electrochemical synthesis, show low limits of detection for hydrogen peroxide, 0.2 and 0.08 [micro]M, and high sensitivity coefficients, 0.71 and 0.84 A M.sup.-1 cm.sup.-2, respectively., Author(s): K. G. Nikolaev [sup.1], S. S. Ermakov [sup.2], Yu. E. Ermolenko [sup.2], D. V. Navolotskaya [sup.2], A. Offenhäusser [sup.3], Yu. G. Mourzina [sup.3] Author Affiliations: (1) grid.35915.3b, 0000 0001 [...]

A multisensor with a four-sectional membrane based on two Li- and two K-ionophores with different selectivities has been developed based on the laser-scanned silicon transducer (LSST), where the responses of the sensor sections have been measured by scanning the potentials at different points on the membrane surface. An artificial neural network (ANN) was employed for the analysis of mixed solutions. It has been demonstrated that by applying this hybrid sensor as a laser-scanned multisensor system, the concentration regions for the simultaneous determination of lithium and potassium ions in complex solutions have been enlarged significantly. It has been shown that using such a kind of multisensor system makes it possible to overcome the restriction of the selectivity in comparison with single sensors. [Copyright &y& Elsevier]