Highly Efficient, Wavelength-Tunable, Gold Nanoparticle Based Optothermal Nanoconvertors

Chou, Cheng-Hsuan; Chen, Cheng-Dah; Wang, C R Chris

doi:10.1021/jp0444520

Cited by 191 publications

(151 citation statements)

References 31 publications

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“…Last, the Au coatings are especially attractive because of the possibility of conjugating the particles with specific molecules such as antibodies, specific ligands, thiol functional groups and therapeutic drugs, opening up prospects for targeted molecular imaging (20). An additional imaging modality built into our nanoconstruct is the optical thermal conversion capability making these structures highly suited for photothermal therapy (32,(38)(39)(40)(41).…”

Section: B and Dmentioning

confidence: 99%

Picomolar sensitivity MRI and photoacoustic imaging of cobalt nanoparticles

Bouchard

Anwar

Liu

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

172

127

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Multimodality imaging based on complementary detection principles has broad clinical applications and promises to improve the accuracy of medical diagnosis. This means that a tracer particle advantageously incorporates multiple functionalities into a single delivery vehicle. In the present work, we explore a unique combination of MRI and photoacoustic tomography (PAT) to detect picomolar concentrations of nanoparticles. The nanoconstruct consists of ferromagnetic (Co) particles coated with gold (Au) for biocompatibility and a unique shape that enables optical absorption over a broad range of frequencies. The end result is a dual-modality probe useful for the detection of trace amounts of nanoparticles in biological tissues, in which MRI provides volume detection, whereas PAT performs edge detection.dual-modality imaging ͉ ferromagnetic nanoparticle ͉ molecular imaging ͉ MRI contrast ͉ photoacoustic tomography W e have synthesized nanoparticles for dual-modality (1-7)MRI and photoacoustic tomography (PAT). The incorporation of MRI and PAT into a single probe offers the unique possibility of combining the complementary strategies of contrastbased volume imaging and edge detection. Our nanoconstruct consists of zero-valence ferromagnetic cobalt (Co) particles (8) with a gold (Au) coating for biocompatibility and a unique shape rendering increased optical absorption over a broad range of frequencies (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). This research theme follows the rapid developments in nanotechnology, diagnostic radiology, and targeted molecular imaging (20), whereby nanoparticulate contrast agents, with the desirable properties of high chemical specificity, biocompatibility, and a reasonable half-life, are administered within a specific region of interest. In nanoparticle-based imaging studies, higher particle concentrations lead to better signal-to-noise contrasts, but this also poses a tradeoff with the toxicity. Therefore, one of the most important parameters when developing particle-based contrast is the safest and lowest nanoparticle concentration that offers sufficient contrast sensitivity.In MRI, magnetic materials such as gadolinium chelates and magnetic nanoparticles are often used (21-23) to enhance image contrast. The magnetic nanoparticles are passivated by biocompatible coatings such as dextrin, citrate, polystyrene/divinylbenzene, and elemental gold. These coatings also detoxify the particles, resulting in enhanced lifetimes in vivo. Typical examples of magnetic nanoparticulate core-shell configurations include magnetitedextrin, magnetite-silica (24) and iron-gold (25).Laser-based PAT (9-19) is a hybrid imaging modality [see supporting information (SI) Fig. S1]. It uses a pulsed laser source to illuminate a biological sample. Light absorption by the tissue results in a transient temperature rise on the order of 10 mK. The rapid thermoelastic expansion excites ultrasonic waves that are measured by using broadband ultrasonic transducers conformally arranged around the sample. Finally, a modif...

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Section: B and Dmentioning

confidence: 99%

Picomolar sensitivity MRI and photoacoustic imaging of cobalt nanoparticles

Bouchard

Anwar

Liu

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

172

127

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“…12,13 Further the temperature rise can be made sufficiently high to cause cell death by hyperthermia, which has potential for important therapeutic applications. [14][15][16] In the last mentioned application, the ability to redshift LP peaks by tailoring the dimensions of the GNRs coupled with the fact that biological tissue is relatively transparent in the red and NIR wavelengths makes GNRs very attractive.…”

Section: Introductionmentioning

confidence: 99%

Discrete dipole approximation simulations of gold nanorod optical properties: Choice of input parameters and comparison with experiment

Ungureanu

Rayavarapu

Manohar

et al. 2009

Journal of Applied Physics

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Gold nanorods have interesting optical properties due to surface plasmon resonance effects. A variety of biomedical applications of these particles have been envisaged and feasibilities demonstrated in imaging, sensing, and therapy based on the interactions of light with these particles. In order to correctly interpret experimental data and tailor the nanorods and their environments for optimal use in these applications, simulations of the optical properties of the particles under various conditions are essential. Of various numerical methods available, the discrete dipole approximation (DDA) approach implemented in the publicly available DDSCAT code is a powerful method that had proved popular for studying gold nanorods. However, there is as yet no universal agreement on the shape used to represent the nanorods and on the dielectric function of gold required for the simulations. We systematically study the influence of these parameters on simulated results. We find large variations in the position of plasmon resonance peaks, their amplitudes, and shapes of the spectra depending on the choice of the parameters. We discuss these in the light of experimental optical extinction spectra of gold nanorods synthesized in our laboratory. We show that much care should be taken and prudence applied before DDA results be used to interpret experimental data and to help characterize nanoparticles synthesized.

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“…A similar valve was constructed by Sershen et al (2005) by synergizing the optical properties of gold-silicon nanoshells with the thermal response capabilities of a thermally responsive polymer hydrogel.. In particular, coupling thermally responsive polymers to metallic nanoparticles has allowed the development of materials that can be triggered both optically and thermally since the incorporated metallic nanoparticles act as amplifiers and converters of light of a specific wavelength into heat (Chou et al, 2005). There are two major advantages of these materials over the traditional optically responsive polymers (using dyes).…”

Section: Constructing Non-mechanical Valves Using Hybrid Responsive Mmentioning

confidence: 99%

Environmentally responsive polymeric "intelligent" materials: the ideal components of non-mechanical valves that control flow in microfluidic systems

Morones‐Ramírez¹

2010

Braz. J. Chem. Eng.

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-Miniaturization and commercialization of integrated microfluidic systems has had great success with the development of a wide variety of techniques in microfabrication, since they allowed their construction at a low cost and by following simple step-series procedures. However, one of the major challenges in the design of microfluidic systems is to achieve control of flow and delivery of different chemical reagents. This feature is especially important when using microfluidic systems in the development of cell culture systems, the construction of labs on a chip and the fabrication and design of chemical microreactors. Spatiotemporal control of the microenvironment in microfluidic devices has been only partially achieved by incorporating actuator parts (mechanical and non-mechanical) within these devices; nevertheless, recently there has been enormous progress due to advances in the materials sciences, and the development of novel polymeric "intelligent" materials. These materials have proved to be excellent candidates in the construction of non-mechanical actuators in the form of environmentally responsive valves. These valves can more efficiently control flows because these "intelligent" materials are capable of undergoing conformational changes and phase transitions in response to different local or external environmental stimuli; allowing them to turn the valves from "on" to "off". In addition, these valves have very simple designs, and are easy and cheap to incorporate into microfluidic systems. Therefore, although there are many reviews that focus on the development and design of non-mechanical actuators, the following review proceeds to describe the exciting characteristics, potential uses and synthesis methods of the building blocks of the most recent and innovative non-mechanical valves, environmentally responsive polymeric "intelligent" materials. In addition, the last section of this review will focus on the synthesis of composite materials that are capable of responding to more than one type of stimulus, since these materials are believed to be the future components that will boost the development of microfluidic systems with spatiotemporal controlled microenvironments.

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Highly Efficient, Wavelength-Tunable, Gold Nanoparticle Based Optothermal Nanoconvertors

Cited by 191 publications

References 31 publications

Picomolar sensitivity MRI and photoacoustic imaging of cobalt nanoparticles

Picomolar sensitivity MRI and photoacoustic imaging of cobalt nanoparticles

Discrete dipole approximation simulations of gold nanorod optical properties: Choice of input parameters and comparison with experiment

Environmentally responsive polymeric "intelligent" materials: the ideal components of non-mechanical valves that control flow in microfluidic systems

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