Optical imaging with subnanometric vertical resolution using nanoparticle-based plasmonic probes

Scarpettini, Alberto F.; Pellegri, N.; Bragas, Andrea V.

doi:10.1016/j.optcom.2008.11.048

Cited by 10 publications

(22 citation statements)

References 21 publications

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“…Because of this interaction, metallic NPs can modify the emission of fluorescent molecules by increasing the excitation and emission rates, as well as by modifying the nonradiative energy transfer from the molecule to the particle (quenching effect). This behavior operates at distances on the order of the nanostructure size, and it is strongly influenced by the chromophore−surface distance, the overlap between the plasmon and the molecular transition bands (absorption and emission), the orientation of the molecular transition moment, the molecular fluorescence emission quantum yield, as well as the NP size, shape, and composition (Coronado et al, ; Noguez, ; Scarpettini, Pellegri, & Bragas, ). The distance‐dependent changes in excitation, emission, and nonradiative energy transfer rates yield an overall fluorescence quenching at very short distances from the NP, whereas emission enhancement is observed at intermediate distances and no influence results for a molecule placed at a distance greater than about twice the NP radius (Simoncelli et al, ).…”

Section: Introductionmentioning

confidence: 99%

“…The regions of emission enhancement (or hot spots), distributed in the direction of polarization of the incident light (Scarpettini et al, 2009), have been used in a wide range of applications, such as high-spatialresolution probes for microscopy (Anger, Bharadwaj, & Novotny, 2006;Noguez, 2007) and nanoscale plasmonic devices (Li, Stockman, & Bergman, 2003;Zou & Schatz, 2006) among others. It has also been shown that due to the excitation of surface plasmons in metal NPs, the enhanced fields give rise to detectable two-photon absorption in the metal (Aaron et al, 2007;Beversluis, Bouhelier, & Novotny, 2003).…”

Section: Introductionmentioning

confidence: 99%

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A tracking‐based nanoimaging method for fast detection of surfaces' inhomogeneities using gold nanoparticles

et al. 2019

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The localization of surfaces inhomogeneities is central to many areas of technology, chemistry and biology, ranging from surface defects in industry to the identification and screening of early bio‐defects inside cells. The development of methods that enable direct, sensitive, and rapid detection of those inhomogeneities is both relevant and timely. To address this challenge, we developed a far‐field nanoimaging method to detect the presence of surface's nanodefects that modify the signal emitted by gold nanoparticles (AuNPs) under laser irradiation. Our technique is based on the formation of hot spots due to the confinement of light in the proximity of the AuNP, whose positions depend on the polarization direction of the incident beam. An inhomogeneity is detected as an increase in the intensity collected from the hot spots when a laser beam is orbiting the nanoparticle and the incident polarization direction of the laser beam is changed periodically.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A tracking‐based nanoimaging method for fast detection of surfaces' inhomogeneities using gold nanoparticles

et al. 2019

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“…Uno de los objetivos de la plasmónica es el control preciso de las propiedades ópticas de la materia nanoestructurada con el fin de lograr, por ejemplo, sensores eficientes y sensibles [1,2], fuentes de luz ultra compactas [3], espectroscopías de moléculas individuales [4,5], terapias fototérmicas contra el cáncer [6,7], microscopías ópticas de resolución nanométrica [8,9], celdas solares [10], entre otras aplicaciones. Para lograr esto es indispensable el diseño a medida de nanoestructuras, su fabricación con alta eficiencia y repetitividad, y el control preciso de sus formas y dimensiones.…”

Section: Introductionunclassified

Recubrimiento controlado de sustratosde vidrio con nanobastones metálicos

2015

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RESUMENSe realizó la síntesis de nanobastones de oro monodispersos con una eficiencia superior al 80% sobre el total de nanopartículas, caracterizado por una resonancia plasmónica longitudinal cercana a los 800 nm. Se modificaron superficialmente sustratos de vidrio y se los recubrió con los nanobastones sintetizados, con control de la densidad superficial. Se monitoreó la dinámica del recubrimiento a través de espectros de extinción, y se observó una densidad máxima de saturación dada por repulsión electrostática y un tiempo característico del proceso. Luego de alcanzada la saturación de nanobastones por unidad de área se observa un ensanchamiento de las resonancias hacia el infrarrojo, debido a interacciones entre los nanobastones por producirse agregaciones sobre la superficie. Estos resultados tienen aplicación inmediata en el diseño y fabricación de dispositivos plasmónicos, por ejemplo en el sensado molecular.Palabras clave: Nanobastones de oro, Plasmónica, Sustratos nanoestructurados. ABSTRACTMonodispersed gold nanorods were synthesized with efficiency above 80% of all nanoparticles, characterized by longitudinal plasmon resonance around 800 nm. Glass substrates were surface modified and covered with the synthesized nanorods with control of surface density. Coverage dynamics was monitored through extinction spectra, and a saturation maximum density was observed, given by electrostatic repulsion, and a characteristic time of the process. A widening of the resonance towards the infrared is observed after reaching the saturation of nanorods per unit area, due to interactions between nanorods on account of surface aggregation. These results have immediate application in the design and manufacture of plasmonic devices, for example in molecular sensing.Keywords: Gold nanorods, Plasmonics, Nanostructured substrates. INTRODUCCIÓNUno de los objetivos de la plasmónica es el control preciso de las propiedades ópticas de la materia nanoestructurada con el fin de lograr, por ejemplo, sensores eficientes y sensibles [1,2], fuentes de luz ultra compactas [3], espectroscopías de moléculas individuales [4,5], terapias fototérmicas contra el cáncer [6,7], microscopías ópticas de resolución nanométrica [8,9], celdas solares [10], entre otras aplicaciones. Para lograr esto es indispensable el diseño a medida de nanoestructuras, su fabricación con alta eficiencia y repetitividad, y el control preciso de sus formas y dimensiones.En esta línea, los nanobastones de oro (NBOs) son atractivos por su simplicidad y porque poseen resonancias plasmónicas superficiales en el rango visible e infrarrojo del espectro electromagnético. La longitud de onda de estas resonancias depende, entre otros factores, de las dimensiones de los NBOs. Si se tiene control sobre su relación de aspecto se puede sintonizar una resonancia relativamente angosta [11]. De este modo es posible construir un dispositivo plasmónico resonante a una longitud de onda deseada, sintetizando NBOs de dimensiones adecuadas y fabricando una nanoestructura usando los NBOs co...

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“…Design of plasmonic nanostructures with remarkable optical antenna properties such as strong confinement and high-field enhancement became one of the central issues in optical nearfield imaging with nanometre spatial resolution (Eghlidi et al, 2009;Scarpettini et al, 2009Barcelo et al, 2012Umakoshi ‡ Balzarotti & Stefani, 2012, Johnson et al, 2012Höppener et al, 2012;De Angelis et al, 2010;Cherukulappurath et al, 2013). Experimental efforts to obtain better, robust and repeatable plasmonic probes are necessarily complemented with calculations of the enhancement factors as a measure of the potential performance of a given new design (Esteban et al, 2009;Perassi et al, 2011;Esteban et al, 2012;Alonso-González et al, 2012;Maximiano et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Harmonic demodulation and minimum enhancement factors in field‐enhanced near‐field optical microscopy

Scarpettini

Bragas

2014

Journal of Microscopy

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Field-enhanced scanning optical microscopy relies on the design and fabrication of plasmonic probes which had to provide optical and chemical contrast at the nanoscale. In order to do so, the scattering containing the near-field information recorded in a field-enhanced scanning optical microscopy experiment, has to surpass the background light, always present due to multiple interferences between the macroscopic probe and sample. In this work, we show that when the probe-sample distance is modulated with very low amplitude, the higher the harmonic demodulation is, the better the ratio between the near-field signal and the interferometric background results. The choice of working at a given n harmonic is dictated by the experiment when the signal at the n + 1 harmonic goes below the experimental noise. We demonstrate that the optical contrast comes from the nth derivative of the near-field scattering, amplified by the interferometric background. By modelling the far and near field we calculate the probe-sample approach curves, which fit very well the experimental ones. After taking a great amount of experimental data for different probes and samples, we conclude with a table of the minimum enhancement factors needed to have optical contrast with field-enhanced scanning optical microscopy.

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Optical imaging with subnanometric vertical resolution using nanoparticle-based plasmonic probes

Cited by 10 publications

References 21 publications

A tracking‐based nanoimaging method for fast detection of surfaces' inhomogeneities using gold nanoparticles

A tracking‐based nanoimaging method for fast detection of surfaces' inhomogeneities using gold nanoparticles

Recubrimiento controlado de sustratosde vidrio con nanobastones metálicos

Harmonic demodulation and minimum enhancement factors in field‐enhanced near‐field optical microscopy

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