Tin Oxide Nanorod Array-Based Electrochemical Hydrogen Peroxide Biosensor

SnO2 nanorod array grown directly on alloy substrate has been employed as the working electrode of H2O2 biosensor. Single-crystalline SnO2 nanorods provide not only low isoelectric point and enough void spaces for facile horseradish peroxidase (HRP) immobilization but also numerous conductive channels for electron transport to and from current collector; thus, leading to direct electrochemistry of HRP. The nanorod array-based biosensor demonstrates high H2O2 sensing performance in terms of excellent sensitivity (379 μA mM−1 cm−2), low detection limit (0.2 μM) and high selectivity with the apparent Michaelis–Menten constant estimated to be as small as 33.9 μM. Our work further demonstrates the advantages of ordered array architecture in electrochemical device application and sheds light on the construction of other high-performance enzymatic biosensors

Zirconium tin titanate thin films via aqueous polymeric precursor route

Zirconium titanate-based thin films are considered as a promising dielectric material for the next generation of integrated microwave devices. The zirconium tin titanate (ZTS) precursor was prepared via a polymeric precursor process in aqueous phase. based on the citrate route. The presented chemical procedure is original for this kind of materials. C-13 nuclear magnetic resonance (NMR) spectra showed that stable mixed-metal chelate complex has been formed. The viscous resin was multiple spin-coated with intermediate firings at 300 degreesC onto platinized Si substrates and fired in air at 700 degreesC. Thin films 200-nm thick were obtained. Atomic force microscope (AFM) analysis showed that the coverage is homogeneous, the surface texture consisting of elongated grains of average size 20 X 36 nm. Grazing incidence X-ray diffraction analysis (GIXRD) indicated that only the zirconium tin titanate phase is present within the examined range of penetration depth. (C) 2001 Elsevier Science BN. AA rights reserved

Photoelectrical Properties of 1.3μm Emitting InAs Quantum Dots in InGaAs Matrix

We present a study of photoelectrical properties of the Stranski-Krastanow InAs quantum dots embedded in an InGaAs matrix with low In content, emitting at about 1.3μm. The ground-state electron-hole transition of the dots was investigated as a function of the temperature in presence of electric fields parallel and perpendicular to the plane of the dots by photocurrent spectroscopy. Microphotoluminescence measurements were also carried out, allowing us to evidence carrier capture from the GaAs matrix into the dots