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Electrochemical sensors for monitoring biochemical substances are attracting considerable attention. These devices are usually based on enzymes that are sensitive and very specific. Still, the activity of those enzymes is lost with changes in temperature or pH. Non-enzymatic electrochemical sensors – fabricated via the modification of the electrode surface with metal oxide nanoparticles – are an ideal answer to address that problem. In this study, we investigated the photo-electrochemical properties of CuO–TiO2 heterojunctions for glucose sensing in alkaline media. A combination of high-resolution (scanning) transmission electron microscopy, spatially resolved electron energy-loss spectroscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction, was used to study in detail the microstructures of the prepared specimens. These results highlighted the strong intertwining between the TiO2 nanoparticles and the Cu-based nanoparticles, which present a metallic core with a CuO rich surface. In addition, we showed that CuO, joint to TiO2, has smaller size compared to pure CuO, which entails larger specific surface area available for the glucose electro-oxidation, which consequently enhanced the electrochemical features. The influence of Cu loading over the sensing performance of TiO2 was examined in detail carrying out electrochemical sensing tests under dark, laboratory and halogen lamp irradiation conditions. Results demonstrated that, under halogen lamp irradiation, modified CuO–TiO2 electrodes showed a specific response signal that is four times higher than that of pure CuO. Those increased photo-electrochemical properties in CuO–TiO2 heterojunctions are likely due to a synergistic effect between the microstructural characteristics and effective separation of photo-generated excitons created at the heterojunction interface. Results of this study offer applicable guidelines for designing photo-electrochemical screen-printed electrodes based on nano-sized CuO on titania for efficient detection of glucose. [ABSTRACT FROM AUTHOR]

B-site Fe-doped (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 was synthesized by a facile chemical route to study the effect of doping on its physical properties. Detailed analysis of X-ray diffraction and Raman spectroscopy data revealed an increased lattice strain and thereby deviation from the morphotropic phase boundary with the progressive doping of Fe from 1 to 5 mol%. Such structural changes have resulted in the weakening of the energy band gap as well as deterioration of the ferroelectric polar nature which was evidenced by a shift of tetragonal to cubic transitions towards room temperature and hard doping effects in ferroelectric hysteresis. The doped samples exhibited room temperature ferromagnetism. Combined Mossbauer and X-ray photoelectron spectroscopic studies suggest that oxygen vacancies and defect complexes induced by Fe doping play a major role in magnetic properties. Local piezoresponse measurements illustrated imprint characteristics of ferroelectric domains in undoped and doped samples at the nanoscale. Room temperature magnetoelectric (ME) measurements revealed that 1 mol% Fe doped sample, having higher ferroelectric polarization and moderate magnetization, exhibits a strong ME response with a coefficient of 12.8 mV cm−1 Oe−1. The present study on Fe-doping effects on the structure and related ME properties of this important lead-free material is useful to tailor multiferroic applications in electronics. [ABSTRACT FROM AUTHOR]