Facile integration of ordered nanowires in functional devices

The integration of one-dimensional (1D) nanostructures of non-industry-standard semiconductors infunctional devices following bottom-up approaches is still an open challenge that hampers the exploita-tion of all their potential. Here, we present a simple approach to integrate metal oxide nanowires inelectronic devices based on controlled dielectrophoretic positioning together with proof of conceptdevices that corroborate their functionality. The method is flexible enough to manipulate nanowiresof different sizes and compositions exclusively using macroscopic solution-based techniques in conven-tional electrode designs. Our results show that fully functional devices, which display all the advantagesof single-nanowire gas sensors, photodetectors, and even field-effect transistors, are thus obtained rightafter a direct assembly step without subsequent metallization processing. This paves the way to lowcost, high throughput manufacturing of general-purpose electronic devices based on non-conventionaland high quality 1D nanostructures driving up many options for high performance and new low energyconsumption devices

NH3 sensing with self-assembled ZnO-nanowire μHP sensors in isothermal and temperature-pulsed mode

Dielectrophoretic alignment is found to be a simple and efficient method to deposit the solution prepared ZnO nanowires onto micro hot plate substrates. Due to the strong surface effects, positive temperature coefficient for resistance was encountered with ZnO nanowires in the high temperature range (>250 degrees C). The response to ammonia (NH3) was evaluated in isothermal and temperature-pulsed operation mode; the relative higher response observed in the latter case demonstrates that the use of this methodology is a good strategy to improve the performance of metal oxide sensors based on nanomaterials. Here, we evaluate the response to NH3 and qualitatively describe the sensing mechanism in temperature-pulsed mode, highlighting the main differences compared to the standard isothermal methodology

Facile integration of ordered nanowires in functional devices

The integration of one-dimensional (1D) nanostructures of non-industry-standard semiconductors in functional devices following bottom-up approaches is still an open challenge that hampers the exploitation of all their potential. Here, we present a simple approach to integrate metal oxide nanowires in electronic devices based on controlled dielectrophoretic positioning together with proof of concept devices that corroborate their functionality. The method is flexible enough to manipulate nanowires of different sizes and compositions exclusively using macroscopic solution-based techniques in conventional electrode designs. Our results show that fully functional devices, which display all the advantages of single-nanowire gas sensors, photodetectors, and even field-effect transistors, are thus obtained right after a direct assembly step without subsequent metallization processing. This paves the way to low cost, high throughput manufacturing of general-purpose electronic devices based on non-conventional and high quality 1D nanostructures driving up many options for high performance and new low energy consumption devices. (C) 2015 Elsevier B.V. All rights reserved

Low Blue Dose Photodynamic Therapy with Porphyrin-Iron Oxide Nanoparticles Complexes: In Vitro Study on Human Melanoma Cells

The purpose of this study was to investigate the effectiveness in photodynamic therapy of iron oxide nanoparticles (γ-Fe2O3 NPs), synthesized by laser pyrolysis technique, functionalized with 5,10,15,20-(Tetra-4-sulfonatophenyl) porphyrin tetraammonium (TPPS) on human cutaneous melanoma cells, after only 1 min blue light exposure. The efficiency of porphyrin loading on the iron oxide nanocarriers was estimated by using absorption and FTIR spectroscopy. The singlet oxygen yield was determined via transient characteristics of singlet oxygen phosphorescence at 1270 nm both for porphyrin functionalized nanoparticles and rose bengal used as standard. The irradiation was performed with a LED (405 nm, 1 mW/cm2) for 1 min after melanoma cells were treated with TPPS functionalized iron oxide nanoparticles (γ-Fe2O3 NPs_TPPS) and incubated for 24 h. Biological tests revealed a high anticancer effect of γ-Fe2O3 NPs_TPPS complexes indi-cated by the inhibition of tumor cell proliferation, reduction of cell adhesion, and induction of cell death through ROS generated by TPPS under light exposure. The biological assays were combined with the pharmacokinetic prediction of the porphyrin

Facile integration of ordered nanowires in functional devices

The integration of one-dimensional (1D) nanostructures of non-industry-standard semiconductors infunctional devices following bottom-up approaches is still an open challenge that hampers the exploita-tion of all their potential. Here, we present a simple approach to integrate metal oxide nanowires inelectronic devices based on controlled dielectrophoretic positioning together with proof of conceptdevices that corroborate their functionality. The method is flexible enough to manipulate nanowiresof different sizes and compositions exclusively using macroscopic solution-based techniques in conven-tional electrode designs. Our results show that fully functional devices, which display all the advantagesof single-nanowire gas sensors, photodetectors, and even field-effect transistors, are thus obtained rightafter a direct assembly step without subsequent metallization processing. This paves the way to lowcost, high throughput manufacturing of general-purpose electronic devices based on non-conventionaland high quality 1D nanostructures driving up many options for high performance and new low energyconsumption devices

NH3 sensing with self-assembled ZnO-nanowire μHP sensors in isothermal and temperature-pulsed mode

Dielectrophoretic alignment is found to be a simple and efficient method to deposit the solution prepared ZnO nanowires onto micro hot plate substrates. Due to the strong surface effects, positive temperature coefficient for resistance was encountered with ZnO nanowires in the high temperature range (>250 degrees C). The response to ammonia (NH3) was evaluated in isothermal and temperature-pulsed operation mode; the relative higher response observed in the latter case demonstrates that the use of this methodology is a good strategy to improve the performance of metal oxide sensors based on nanomaterials. Here, we evaluate the response to NH3 and qualitatively describe the sensing mechanism in temperature-pulsed mode, highlighting the main differences compared to the standard isothermal methodology