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Intense electrolyte loss as a result of excessive sweating can disrupt the electrolyte balance in the body and cause damage to many organs, as well as potentially fatal disturbances in even brain functions. There are commercial sensors developed to monitor users' physical activity, however, few of them can provide information on users' health status through sweat analysis. Herein we report a chemiresistive sensor to monitor the sweat electrolyte concentration level. Metal oxide semiconducting CuO films were deposited on Au electrodes as sensing layers. Ca2+ ions were doped into the CuO lattice as sensitizer. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and UV–Vis spectroscopy were used to characterize the films. Sensors produced with pure and Ca-doped CuO films were tested against different concentrations of artificial sweat. The sensors responded well to sweat electrolyte concentration with a linear detection range of 20–80 mM. Detection limits between 6.64 and 9.86 mM were estimated using standard deviation methods. Average sensor response times were found to be 12 s. [ABSTRACT FROM AUTHOR]

CuO nanostructures with and without Pb were synthesized by the Successive Ionic Layer Adsorption and Reaction method. The films were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and ultraviolet–visible spectrophotometry. Scanning electron microscopy results showed that the morphology of the film surface was changed from plate-like to coral-like nanostructures with increasing Pb concentration. The X-ray diffraction patterns showed the monoclinic crystal structure with preferential planes of ( 1 ¯ 1 1 ) and (1 1 1). Furthermore, ultraviolet–visible spectra showed that the band gap of the films was tailored by Pb doping. [ABSTRACT FROM AUTHOR]

Abstract: In this work, nanostructured CdO films with different coumarin contents in the growth solution were fabricated on glass substrates by the SILAR method. The effects of coumarin content in the bath on optical, structural and morphological properties were studied by means of (UV–vis) spectrophotometer, SEM and XRD analysis. The analysis showed that the band gaps, surface morphologies and XRD peak intensities of the CdO films were found to change with coumarin content. A change in the band gap energy can be attributed to the improvement in crystallinity of the samples. XRD analysis showed that, the films have poly-crystalline structures with decent crystallinity levels. [Copyright &y& Elsevier]

Abstract: Un-doped and Co-doped CdO nanostructures were deposited on glass substrates by successive ionic layer adsorption and reaction (SILAR) method and annealed at 300 and 400°C. Morphological, structural and optical properties of the films were investigated by scanning electron microscope (SEM), X-ray diffractometer (XRD) and ultra violet-vis (UV–vis) spectrophotometry. The analyzed results indicate that Co-doping concentration and annealing temperature affect the properties of nanostructure cadmium oxide (CdO) films. XRD results showed that all of the films are polycrystalline cubic CdO with good crystallinity levels. With UV–vis. analysis at the room temperature it was found that the doping and annealing temperature changed optical properties of CdO films. [Copyright &y& Elsevier]

Abstract: Thin films of un-doped and Mn-doped CuO nanostructures have been deposited on glass substrates via the SILAR method. The morphological, compositional, structural and optical properties of the films have been investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction analysis and UV–vis spectrophotometry. The analyzed results indicate that the obtained films consist of plate-like nanostructures. From the EDS analysis it is seen that Mn-doping concentration affects the shapes of the nanostructures. XRD results show that all of the films have monoclinic structure. From the room temperature UV–vis analysis it is found that the optical band gap of the films increases with increasing Mn-doping concentrations. [Copyright &y& Elsevier]

Highlights: [•] The first study analyzing the impact of coumarin content on CuO nanostructures. [•] Optical bandgap can be manipulated by adjusting the coumarin concentration. [•] Crystallite size can be manipulated by adjusting the coumarin concentration. [•] Transmission characteristics can be tuned accordingly by coumarin concentration. [Copyright &y& Elsevier]

Abstract: Two simple, safe and environmental friendly chemical solution methods which are suitable to mass production, applicable at low temperatures and cost effective, were used to prepare homogenous nano-structured cupric oxide (CuO) films. By using different types of substrates (glass, quartz, Cu foil and Si) and techniques various types of CuO nanostructures (plate, needle and network like) were produced. The products were characterized by scanning electron microscopy, X-ray diffraction and temperature dependant dark electrical resistivity measurements in order to investigate the effects of substrate on morphology, crystallographic structure and electrical properties of the films. From these characterizations it was seen that there are significant differences in the morphological, crystallographic, structural and electrical properties of the nanostructures that were produced by different techniques and/or on different substrates. Besides, growth mechanisms of CuO films have been investigated. [Copyright &y& Elsevier]

Abstract: This paper describes a simple, low temperature and cost effective solution method to synthesize homogenous cupric oxide (CuO) nano-structured thin films. By this method dense and continuous CuO films with good crystallinity can be prepared in a short time, e.g., in 15min. The scanning electron microscopy illustrated that the synthesized CuO plate-like nanostructures have RMS thicknesses of 100nm. The XRD measurements showed that the synthesized CuO nanostructures have a high crystallinity with monoclinic crystal structure preferentially in and (111) directions. From the temperature dependant dark electrical resistivity measurements the ionization energies of the impurity levels and thermal band gap energies of the films were calculated. [ABSTRACT FROM AUTHOR]

Cadmium oxide films with and without silver-doping have been prepared by the SILAR method onto soda-lime-silica glass slides and characterized by scanning electron microscopy, UV-Visible spectroscopy and X-ray diffraction measurements. Scanning electron microscopy images show that increasing silver concentration contributed to adjust surface properties and led to a decrease in particle size from the UV-Visible spectroscopy analysis it was found that the optical band gap value of the films is increased with silver doping. [ABSTRACT FROM AUTHOR]

Abstract: Five series of pure and tin-doped CdO films have been grown on amorphous glass substrates by the successive ionic layer adsorption and reaction (SILAR) method. The film׳s structural, morphological and optical properties have been investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and UV–vis spectrophotometer. XRD results showed that all of the films are polycrystalline cubic CdO. Doping of tin enhances the film׳s (111) preferred orientation and causes slight shift in the (111) Bragg angle towards higher value. From the FESEM images, it was seen that tin-doping concentration affects the shapes of the nanostructures. It was found that the tin-doping concentration modify the microstructures. With UV–vis analysis at the room temperature it was seen that the optical band gap and transmission properties of the films change with increasing tin concentration in the growth bath. [Copyright &y& Elsevier]

Herein the deposition and characterization of CuO films with various doping concentrations of boron through the application of the SILAR method are performed. Structural, morphological, and optical properties of the films are determined by SEM with EDS, XRD, and UV/Vis spectroscopy. EDS analysis proved the boron contributions in the films. SEM images showed that boron-doping has a decreasing effect on particle size i.e. the thickness and the length of the nanostructures decreased from 45 to 30 and from 224 to 150 nm, respectively. XRD analyses demonstrated that the crystallite size of the films increased from 12.9 to 15.9 nm with increasing boron concentration which is evidence for increased crystallinity. UV/Vis spectroscopy analysis demonstrated that band gap energy value effectively decreased by boron doping. • CuO films with different boron-doping are deposited by the SILAR method for the first time. • B-doping decreased the thickness/length of the nanostructures but increased the crystallite size. • It is shown that boron-doping can be used as a band-gap regulator. [ABSTRACT FROM AUTHOR]

Abstract: We have investigated the effects of Al, K and Co dopant elements on the properties of ZnO thin films deposited by CBD method on glass substrates. Changing in morphology, structural parameters, ionization energies of impurity levels, absorption behavior and optical band gap values were investigated through scanning electron microscopy (SEM), X-Ray diffraction (XRD), resistance–temperature measurement (R–T) and ultraviolet–visible spectroscopy (UV–vis) techniques. From the SEM observations, various morphologies (rod-like, flower-like and rice-like) were observed. Those morphological variations were attributed to the change in stable growth mechanism of intrinsic ZnO, induced by different atomic radius and different electronegativity of dopants. XRD results indicated that all orientations are well indexed to hexagonal phase crystalline ZnO. The impurity level ionization energy values (ΔE) were estimated as 0.32/0.13/0.07eV; 0.34/0.15eV; 0.40/0.13eV and 0.48/0.22eV for the Al, K, Co doped samples and i-ZnO, respectively. Optical band gap values were found that the doped samples'' were higher than the intrinsic one''s. This increasing (blue shift) was attributed to a deterioration which occurred in the lattice of the structures after doping. This effect was also supported by the structural results. [Copyright &y& Elsevier]