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So far, poly(L-lactic acid), PLLA nanosheets proved to be promising for wound healing. Such biodegradable materials are easy to prepare, bio-friendly, cost-effective, simple to apply and were shown to protect burn wounds and facilitate their healing. At the same time, certain metal ions are known to be essential for wound healing, which is why this study was motivated by the idea of incorporating PLLA nanosheets with Zn2+ ion containing nanoparticles. Upon being applied on wound, such polymer nanosheets should release Zn2+ ions, which is expected to improve wound healing. The work thus focused on preparing PLLA nanosheets embedded with several kinds of Zn-containing nanoparticles, their characterization and ion-release behavior. ZnCl2 and ZnO nanoparticles were chosen because of their different solubility in water, with the intention to see the dynamics of their Zn2+ ion release in liquid medium with pH around 7.4. Interestingly, the prepared PLLA nanosheets demonstrated quit similar ion release rates, reaching the maximum concentration after about 10 h. This finding implies that such polymer materials can be promising as they are expected to release ions within several hours after their application on skin. [ABSTRACT FROM AUTHOR]

Nanostructured ZnO thin films were spray pyrolysis deposited on glass substrates using the zinc acetate dihydrate as precursor at the substrate temperature of 523 K. The effect of precursor solution volume on the structural, morphological, electrical, optical and gas sensing properties of ZnO thin film was investigated. The growth of nanopetals morphology was observed for the film deposited using 30 ml. Enhanced electrical conductivity was observed for the film with nanopetals morphology but the optical transmittance was found to be decreased up to 25% than that of other films. The influence of tensile and compressive stress in the prepared samples was investigated. Further the room temperature acetaldehyde sensing behaviour of the ZnO film deposited using 45 ml precursor volume is reported. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanostructures were grown on glass substrates using hydrothermal technique followed by a sputter deposited ZnO seed layer. The influence of hexamethylenetetramine (HMTA) concentrations on the growth of ZnO nanostructures and their room temperature sensing performance were investigated. Further, the non-mutually exclusive dual role of HMTA on the growth of ZnO nanostructures were evaluated by morphological studies. Various morphologies such as nanoprisms, nanoparticles decorated nanoprisms and nanodisks were observed concerning various molar concentrations of zinc acetate and HMTA. Protonation of HMTA acted as a capping agent, which offered a unique impact on the anisotropic growth of ZnO along the c -axis direction. Nanoparticles decorated nanoprisms showed good selectivity towards acetaldehyde vapor amidst ethanol, ammonia, and acetone, which was well supported by bond dissociation energy. The presence of increased number of junction types, densities, and networked structure showed a prospect towards better sensing performance. [ABSTRACT FROM AUTHOR]

Breath analysis has emerged as one of the accurate diagnostic techniques, which can be used to correlate disease conditions with the abnormal concentrations of certain biomarkers present in the exhaled breath. In this background, thin film based chemi-resistive Cerium-doped ZnO sensors were developed for detecting acetone and ethanolamine, which are the notable biomarkers of diabetes mellitus and carcinoma respectively. Ce-doped ZnO thin films were deposited on glass substrates using spray pyrolysis technique. X-ray diffraction patterns confirmed the formation of Ce-doped ZnO thin films with polycrystalline hexagonal wurtzite structure. Scanning electron micrographs and optical absorption spectra of Ce-doped ZnO thin films revealed the decrease in average grain size and increase in band gap respectively with an increase in Ce-dopant concentration. ZnO films with 0.004 and 0.008 M of Ce-dopant concentrations showed a better room temperature sensing response towards acetone and ethanolamine respectively. Highly selective nature of the developed sensing elements towards acetone and ethanolamine with swift response and recovery times can be considered as a non-invasive and cost effective method for the detection of diseases like diabetes mellitus and carcinoma. [ABSTRACT FROM AUTHOR]

Highlights: [•] Undoped and Fe-doped ZnO thin films were spray deposited on glass substrates. [•] Morphology transition from nanospheres to nanorods was observed while doping Fe. [•] Grain size was increased with increase in Fe dopant concentration. [•] Optical band gap was decreased with increase in Fe dopant concentration. [•] Electrical conductivity of the doped film was increased with Fe concentration. [ABSTRACT FROM AUTHOR]