A nanoplasmonic molecular ruler for measuring nuclease activity and DNA footprinting

Liu, Gang L.; Yin, Yadong; Kunchakarra, Siri; Mukherjee, Bipasha; Gerion, Daniele; Jett, Stephen D.; Bear, David G.; Gray, Joe W.; Alivisatos, A. Paul; Lee, Luke P.; Chen, Fanqing Frank

doi:10.1038/nnano.2006.51

Cited by 262 publications

(167 citation statements)

References 29 publications

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“…Heat absorbing and neutral density filters were used to ensure radiant flux densities are below the damage threshold of the DNA origami structures. In all cases, the presence of the DNA changes the dielectric properties of the environment around the NPs, allowing an effective refractive index for both layers to be calculated 38 .…”

Section: Resultsmentioning

confidence: 99%

DNA origami based assembly of gold nanoparticle dimers for surface-enhanced Raman scattering

et al. 2014

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Plasmonic sensors are extremely promising candidates for label-free single-molecule analysis but require exquisite control over the physical arrangement of metallic nanostructures. Here we employ self-assembly based on the DNA origami technique for accurate positioning of individual gold nanoparticles. Our innovative design leads to strong plasmonic coupling between two 40 nm gold nanoparticles reproducibly held with gaps of 3.3±1 nm. This is confirmed through far field scattering measurements on individual dimers which reveal a significant red shift in the plasmonic resonance peaks, consistent with the high dielectric environment due to the surrounding DNA. We use surface-enhanced Raman scattering (SERS) to demonstrate local field enhancements of several orders of magnitude through detection of a small number of dye molecules as well as short single-stranded DNA oligonucleotides. This demonstrates that DNA origami is a powerful tool for the high-yield creation of SERS-active nanoparticle assemblies with reliable sub-5 nm gap sizes.

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Section: Resultsmentioning

confidence: 99%

DNA origami based assembly of gold nanoparticle dimers for surface-enhanced Raman scattering

et al. 2014

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“…4 electrical/optical levels, which give interesting possibilities for bio-sensing applications [28][29][30][31][32][33][34].…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Microstructural evolution of Au/TiO2 nanocomposite films: The influence of Au concentration and thermal annealing

et al. 2015

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Nanocomposite thin films consisting of a dielectric matrix, such as titanium oxide (TiO 2 ), with embedded gold (Au) nanoparticles were prepared and will be analysed and discussed in detail in the present work. The evolution of morphological and structural features was studied for a wide range of Au concentrations and for annealing treatments in air, for temperatures ranging from 200 to 800 ºC. Major findings revealed that for low Au atomic concentrations (at. %), there are only traces of clustering, and just for relatively high annealing temperatures, T ≥ 500 ºC. Furthermore, the number of Au nanoparticles is extremely low, even for the highest annealing temperature, T = 800 ºC.It is noteworthy that the TiO 2 matrix also crystallizes in the anatase phase for annealing temperatures above 300 ºC.

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“…However, further work on shape optimization will be required to conclusively comment on this. Furthermore, the Au sandwich structure also allows additional tuning of absorbed wavelengths (28,36,37). This can further improve the sensitivity of the PAT technique.…”

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.

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170

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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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A nanoplasmonic molecular ruler for measuring nuclease activity and DNA footprinting

Cited by 262 publications

References 29 publications

DNA origami based assembly of gold nanoparticle dimers for surface-enhanced Raman scattering

DNA origami based assembly of gold nanoparticle dimers for surface-enhanced Raman scattering

Microstructural evolution of Au/TiO2 nanocomposite films: The influence of Au concentration and thermal annealing

Picomolar sensitivity MRI and photoacoustic imaging of cobalt nanoparticles

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