Graphene Decorated with Iron Oxide Nanoparticles for Highly Sensitive Interaction with Volatile Organic Compounds

Gases, such as nitrogen dioxide, formaldehyde and benzene, are toxic even at very low concentrations. However, so far there are no low-cost sensors available with sufficiently low detection limits and desired response times, which are able to detect them in the ranges relevant for air quality control. In this work, we address both, detection of small gas amounts and fast response times, using epitaxially grown graphene decorated with iron oxide nanoparticles. This hybrid surface is used as a sensing layer to detect formaldehyde and benzene at concentrations of relevance (low parts per billion). The performance enhancement was additionally validated using density functional theory calculations to see the effect of decoration on binding energies between the gas molecules and the sensor surface. Moreover, the time constants can be drastically reduced using a derivative sensor signal readout, allowing the sensor to work at detection limits and sampling rates desired for air quality monitoring applications

Непрерывное фармакологическое образование при подготовке врачебных кадров

ОБРАЗОВАНИЕ МЕДИЦИНСКОЕВУЗЫМЕДИЦИНСКИЕ УЧЕБНЫЕ ЗАВЕДЕНИЯОБРАЗОВАНИЕ ФАРМАЦЕВТИЧЕСКОЕ, ПОВЫШЕНИЕ КВАЛИФИКАЦИИ /МЕТОДЫНЕПРЕРЫВНОЕ ФАРМАКОЛОГИЧЕСКОЕ ОБРАЗОВАНИЕМЕДИЦИНСКИЕ КАДР

New Tools for Imaging Neutrophils : Work Function Mapping and Element-Specific, Label-Free Imaging of Cellular Structures

Photoemission electron microscopy and imaging X-ray photoelectron spectroscopy are today frequently used to obtain chemical and electronic states, chemical shifts, work function profiles within the fields of surface- and material sciences. Lately, because of recent technological advances, these tools have also been valuable within life sciences. In this study, we have investigated the power of photoemission electron microscopy and imaging X-ray photoelectron spectroscopy for visualization of human neutrophil granulocytes. These cells, commonly called neutrophils, are essential for our innate immune system. We hereby investigate the structure and morphology of neutrophils when adhered to gold and silicon surfaces. Energy-filtered imaging of single cells are acquired. The characteristic polymorphonuclear cellular nuclei divided into 2-S lobes is visualized. Element-specific imaging is achieved based on O 1s, P 2p, C 1s, Si 2p, and N is core level spectra, delivering elemental distribution with submicrometer resolution, illustrating the strength of this type of cellular morphological studies.Funding Agencies|Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU 2009-00971]; Swedish Research Council VRSwedish Research Council [2019-02409]; Knut and Alice Wallenberg Foundation KAWKnut &amp; Alice Wallenberg Foundation [2014.0276]; CTS [CTS 18:399 19:379]; Centre in Nanoscience and Nanotechnology at LiTH (CeNano) at Linkoping University</p

Step by step rare-earth catalyzed SiOx annealing and simultaneous formation of Europium- silicide by low coverage of Eu doped Gd2O3 nanoparticles

We report the formation of silicide by annealing of a SiOx surface, with low coverage of Eu doped Gd2O3 nanoparticles. The annealing temperature required for removal of native oxide from the Si substrate decreases with close to 200 °C in presence of the nanoparticles. X-ray photoemission electron microscopy, low-energy electron microscopy and mirror electron microscopy are used to monitor the silicide formation and SiOx removal. Fragmentation of the nanoparticles is observed, and the SiOx layer is gradually removed. Eu migrates to clean Si areas during the annealing process, while Gd is found in areas where oxide is still present. This annealing process is clearly facilitated in the presence of rare-earth based nanoparticles, where nanoparticles are suggested to function as reaction sites to catalyze the oxygen removal and simultaneously form Eu based silicide. Reduction of the annealing temperature of SiOx substrates is also observed in presence of pure Eu3+ and Gd3+ ions. Simultaneous oxygen removal and EuSi formation enable this new rare-earth catalyzed annealing and silicide formation to find applications both within optoelectronics and processing microelectronic industry

http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-79152 ZnO materials and surface tailoring for biosensing

materials and surface tailoring for biosensing