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Biomed Microdevices ; 19(3): 60, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28677098


We present a new strategy for fabricating a silicon nanopore device allowing straightforward fluidic integration and electrical as well as optical monitoring. The device presents nanopores of diameters 10 nm to 160 nm, and could therefore be used to obtain solvent-free free-standing lipid bilayers from small unilamellar vesicles (SUV) or large unilamellar vesicles (LUV). The silicon chip fabrication process only requires front side processing of a silicon-on-insulator (SOI) substrate. A polydimethylsiloxane (PDMS) microfluidic interface is assembled on the silicon chip for fluidic handling and electrical addressing. We detail the electrical specifications of our device and some perspectives showing that the use of an SOI substrate is a convenient way to reduce the electrical noise in a silicon nanopore device without the need of a photolitographic patterned passivation layer. We then demonstrate simultaneous electrical and optical monitoring by capturing negatively charged fluorescent nanoparticles. Finally, in the perspective of solvent-free free-standing lipid bilayers, we show that incubation of SUV results in a drastic increase of the device electrical resistance, which is likely due to the formation of a free-standing lipid bilayer sealing the nanopores. Graphical abstract ᅟ.

Corantes Fluorescentes/química , Dispositivos Lab-On-A-Chip , Bicamadas Lipídicas/química , Nanopartículas/química , Nanoporos , Imagem Óptica , Dimetilpolisiloxanos/química , Impedância Elétrica
Nanoscale ; 5(12): 5288-93, 2013 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-23657625


Plasmonic resonance properties of a series of lithographically patterned gold nanorod arrays, spin coated by thin films of an iron(II)-triazole type spin crossover complex, were investigated upon heating/cooling and also under 633 nm laser irradiation. In both cases a reversible shift of the localised surface plasmon resonance wavelength was observed and quantitatively linked to the refractive index change accompanying the spin transition. These results show that molecular spin state switching can be very efficiently triggered by the photo-thermal effect, which - in turn - allows for an active tuning of the plasmon resonance.

J Nanosci Nanotechnol ; 10(8): 5042-50, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21125848


We present a new approach for patterning thin films of Prussian blue at the micro- and nano-metric scales. In a first step, a resist was deposited on a gold surface and patterns were generated by photolithography or electron beam lithography. The Prussian blue with idealized formula of KFe(III)[Fe(II)(CN)6] was deposited through the sequential exposure of the patterned surface to a series of solutions containing alternately absorbable Fe3+ cations and [Fe(CN)6]4- anions. These building blocks are gradually associated into dense and continuous films and patterned structures of Prussian blue can be obtained finally by lift-off. This approach was also used to deposit Prussian blue thin films on interdigitated nanoelectrodes and the current-voltage characteristics of this device were investigated.

Ferrocianetos/química , Nanoestruturas/química , Nanotecnologia/métodos , Condutividade Elétrica , Eletroquímica , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Nanoestruturas/ultraestrutura , Propriedades de Superfície
J Opt Soc Am A Opt Image Sci Vis ; 19(12): 2394-402, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12469733


Characterization of gratings with small period-to-wavelength ratios is difficult to perform but is very helpful in improving the fabrication process. We experimentally tested an inverse-scattering method using a neural network on silicon etched gratings. We also characterized the gratings by using two popular microscopic methods. The validity of each method was determined by comparing measured diffracted intensities with calculated ones obtained from measured profiles. An estimation of accuracy and repeatability was deduced from a scan along a grating sample. This method was thus well validated for nondestructive and noninvasive measurements under experimental conditions that were close conditions of actual usage. This method is easy to implement and requires the measurement of only a few diffracted intensities.