Plasmonic Heating-Assisted Transformation of SiO2/Au Core/Shell Nanospheres (Au Nanoshells): Caveats and Opportunities for SERS and Direct Laser Writing

Alessandri, Ivano; Ferroni, Matteo; Depero, Laura E.

doi:10.1007/s11468-012-9455-0

Cited by 24 publications

(19 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This means that the local temperature exceeds the melting threshold of both a-Si (Melting point bulk : 1414°C) and SiO 2 (Melting point bulk : 1710°C), 19 indicating that the opto-thermal coupling in these system is remarkable. These results are similar to those observed for SiO 2 /Au beads irradiated with a Raman laser under analogous conditions 20 and suggest that, in particular systems, non-plasmonic heating can be as efficient as the plasmonic one. These processes were directly monitored by Raman spectroscopy (Figures 1c and d).…”

supporting

confidence: 84%

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

Bontempi¹,

Vassalini²,

Danesi³

et al. 2018

Preprint

Self Cite

View full text Add to dashboard Cite

Resonant Laser PrintingAll-dielectric and semiconductor-based optical antennas are intensively investigated as promising substrates for surface enhanced Raman scattering (SERS). 1 This emerging interest stems from several factors. One is the possibility to exploit a rich variety of opportunities to tune the Raman response. For example, the chemical enhancement can be widely modulated by controlling charge transfer and adsorption-induced changes of the molecular polarizability of a given analyte.In parallel, the electromagnetic enhancement can take advantage of Mie-type resonances, light trapping and related optical effects to increase sensitivity and selectivity of the Raman response.Further major benefits of non-plasmonic SERS are low-invasiveness (plasmonic heating and plasmon-driven catalysis are avoided) 2-6 and high reproducibility, which make dielectrics more advantageous than metals for many types of Raman analysis, including the real-time monitoring of chemical reactions. These hallmarks are ultimately related to the lossless nature of dielectrics, which avoids the generation of strong local heating under light irradiation. Among the different types of dielectrics and semiconductors that have been proposed so far, SiO 2 /TiO 2 core/shell beads (T-rex) 7 demonstrated unique performances in sensing environmental pollutants and biomarkers. 6-10In particular, micron-sized beads can be individually visualized by optical microscopy and exploited as Mie resonators able to act as all-in-one colloidal platforms combining SERS, mass spectrometry and optical sensing. 11 As the SERS efficiency of these resonators is closely related to the refractive index contrast between core and shell, the replacement of the TiO 2 with a higher index material could further improve the performance of these systems. 12 In this regard, Si represents a natural choice in terms of high refractive index (n∼4 at the most common Raman exciting wavelengths) and compatibility with sensing devices. [13][14][15] Maier and co-workers demonstrated that dimers of spheres and nanodisks, either made of GaP or Si, are able to produce a good near-field enhancement, yet with minimal heating losses if compared with the analogous gold counterparts. (100) substrates by rf-magnetron sputtering and selected for the study (details in Supporting Information, SI 1 and SI 2). The laser spot size of the three wavelengths is commensurate with the 2 µm-sized beads, which enables a geometrically efficient light in-coupling. On the other hand, the laser spot size is about 1/3 of that of the whole sphere in the case of∼ 6.5 µm-sized cores. Both single beads and three-dimensional (3D) colloidal crystals were analysed. ) Raman spectra of the samples before (blue) and after (red) 500s of exposure to an exciting laser beam (laser wavelength: 633 nm, power: 5mW); c) 6_Si100 and d) 2_Si100 samples: e) Raman intensity ratio (IαSi/IcSi) as function of time respectively for 6_Si100 (pink) and for 2_Si100 (light blue); f) Threshold laser power as function of shell thickness...

show abstract

supporting

confidence: 84%

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

Bontempi¹,

Vassalini²,

Danesi³

et al. 2018

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Great promises are related to the use of high‐refractive‐index materials, such as silicon. However, the optothermal properties of these materials should be judiciously designed and controlled, in order not to slip back into the limitations typical of plasmonic metals . The other factor that controls the optical response of these systems is the shape.…”

Section: Discussionmentioning

confidence: 99%

“…However, the optothermal properties of these materials should be judiciously designed and controlled, in order not to slip back into the limitations typical of plasmonic metals. [32] The other factor that controls the optical response of these systems is the shape. All the examples described above are referred to spherical resonators, but interesting opportunities for light management at the nanoscale are expected also for other shapes (nanowires, nanodots, nanoribbons, …).…”

Section: Discussionmentioning

confidence: 99%

All‐dielectric core/shell resonators: From plasmon‐free SERS to multimodal analysis

Bontempi

Vassalini

Alessandri

2018

J Raman Spectroscopy

Self Cite

View full text Add to dashboard Cite

All‐dielectric materials are emerging as a new class of substrates for enhanced Raman scattering. As ohmic losses are reduced in the absence of plasmonic metals, Raman data obtained with dielectrics are very reproducible and reliable. This mini‐review summarizes our recent work in the field of core/shell dielectric resonators designed for Raman purposes, with a special focus on SiO2/TiO2 (T‐rex) core/shell beads. These systems are able to exploit the evanescent field generated by total internal reflection and multiple scattering of light at the sphere‐to‐sphere interface to multiply the number of Raman photons, improving the sensitivity of Raman detection and extending the application of surface enhanced Raman scattering for investigating surface chemical reactions. Examples of the application of T‐Rex beads in detecting and monitoring environmental pollutants, greenhouse gases, biochemical species, and biochemical reactions are presented. The use of core/shell resonators for multimodal analysis based on the combination of surface enhanced Raman scattering with either mass spectrometry or refractive index optical sensing is also discussed, suggesting different possible future developments.

show abstract

“…Despite the fact that the main interest with plasmonic nanostructures is more concentrated on cancer therapy and diagnosis, these particles have had a significant influence on other fields of science as well. 36 Numerous nanostructures different in shape, material, and structure, and therefore in chemical, physical, and optical properties have been and are being introduced and exploited for various applications. Among the variety of nanoparticles developed so far, nanoshells, introduced for the first time by Halas et al, present a new family of materials with tunable plasmon band, throughout the visible and into the infrared region of the electromagnetic spectrum.…”

Section: Introductionmentioning

confidence: 99%

Barium titanate core – gold shell nanoparticles for hyperthermia treatments

FarrokhTakin¹,

Ciofani²,

Puleo³

et al. 2013

IJN

View full text Add to dashboard Cite

Abstract:The development of new tools and devices to aid in treating cancer is a hot topic in biomedical research. The practice of using heat (hyperthermia) to treat cancerous lesions has a long history dating back to ancient Greece. With deeper knowledge of the factors that cause cancer and the transmissive window of cells and tissues in the near-infrared region of the electromagnetic spectrum, hyperthermia applications have been able to incorporate the use of lasers. Photothermal therapy has been introduced as a selective and noninvasive treatment for cancer, in which exogenous photothermal agents are exploited to achieve the selective destruction of cancer cells. In this manuscript, we propose applications of barium titanate core-gold shell nanoparticles for hyperthermia treatment against cancer cells. We explored the effect of increasing concentrations of these nanoshells (0-100 µg/mL) on human neuroblastoma SH-SY5Y cells, testing the internalization and intrinsic toxicity and validating the hyperthermic functionality of the particles through near infrared (NIR) laser-induced thermoablation experiments. No significant changes were observed in cell viability up to nanoparticle concentrations of 50 µg/mL. Experiments upon stimulation with an NIR laser revealed the ability of the nanoshells to destroy human neuroblastoma cells. On the basis of these findings, barium titanate core-gold shell nanoparticles resulted in being suitable for hyperthermia treatment, and our results represent a promising first step for subsequent investigations on their applicability in clinical practice.

show abstract

Plasmonic Heating-Assisted Transformation of SiO2/Au Core/Shell Nanospheres (Au Nanoshells): Caveats and Opportunities for SERS and Direct Laser Writing

Cited by 24 publications

References 17 publications

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

All‐dielectric core/shell resonators: From plasmon‐free SERS to multimodal analysis

Barium titanate core – gold shell nanoparticles for hyperthermia treatments

Contact Info

Product

Resources

About

Plasmonic Heating-Assisted Transformation of SiO2/Au Core/Shell Nanospheres (Au Nanoshells): Caveats and Opportunities for SERS and Direct Laser Writing

Cited by 24 publications

References 17 publications

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

All‐dielectric core/shell resonators: From plasmon‐free SERS to multimodal analysis

Barium titanate core &ndash; gold shell nanoparticles for hyperthermia treatments

Contact Info

Product

Resources

About

Barium titanate core – gold shell nanoparticles for hyperthermia treatments