Determination of melatonin by potentiometric stripping analysis using sensor based on boron-doped diamond electrodes.

A three-electrode screen-printed sensor with heavily doped microcrystalline boron-doped diamond electrodes grown by chemical vapor deposition on alumina substrates was used to determine the concentration of melatonin by constant current potentiometric stripping analysis. This paper provides a detailed examination of the irreversible oxidation behavior of melatonin by cyclic voltammetry at a boron-doped diamond electrode. The relationship between the current response and the square root of the scan rate confirmed a diffusion-controlled oxidation process.

Laser-Induced Periodic Surface Structures and Their Application for Gas Sensing.

Semiconducting metal oxides are widely used for solar cells, photo-catalysis, bio-active materials and gas sensors. Besides the material properties of the semiconductor being used, the specific surface topology of the sensors determines device performance. This study presents different approaches for increasing the sensing area of semiconducting metal oxide gas sensors.

Analysis of nanocrystalline films on rough substrates.

In this work, we propose a method to estimate basic parameters like the rms roughness and the mean grain size of nanocrystalline thin films on rough substrates. The method is based on the analysis of the power spectral density (PSD) of the surface profile, which allows distinguishing between the two participating components from surface and film. The effectiveness will be demonstrated for thin NiO(x) layers for gas sensing on Al(2)O(3) ceramic substrates, and for protective WC coatings on steel.