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Nanoparticle

About: Nanoparticle is a research topic. Over the lifetime, 85905 publications have been published within this topic receiving 2689382 citations. The topic is also known as: nanoparticles.


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Journal ArticleDOI
21 Feb 1997-Science
TL;DR: In this article, surface-enhanced Raman scattering was used to detect single molecules and single nanoparticles at room temperature with the use of surface enhanced Raman, and the intrinsic Raman enhancement factors were on the order of 10 14 to 10 15, much larger than the ensemble-averaged values derived from conventional measurements.
Abstract: Optical detection and spectroscopy of single molecules and single nanoparticles have been achieved at room temperature with the use of surface-enhanced Raman scattering. Individual silver colloidal nanoparticles were screened from a large heterogeneous population for special size-dependent properties and were then used to amplify the spectroscopic signatures of adsorbed molecules. For single rhodamine 6G molecules adsorbed on the selected nanoparticles, the intrinsic Raman enhancement factors were on the order of 10 14 to 10 15 , much larger than the ensemble-averaged values derived from conventional measurements. This enormous enhancement leads to vibrational Raman signals that are more intense and more stable than single-molecule fluorescence.

9,609 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe recent progress in the theory of nanoparticle optical properties, particularly methods for solving Maxwell's equations for light scattering from particles of arbitrary shape in a complex environment.
Abstract: The optical properties of metal nanoparticles have long been of interest in physical chemistry, starting with Faraday's investigations of colloidal gold in the middle 1800s. More recently, new lithographic techniques as well as improvements to classical wet chemistry methods have made it possible to synthesize noble metal nanoparticles with a wide range of sizes, shapes, and dielectric environments. In this feature article, we describe recent progress in the theory of nanoparticle optical properties, particularly methods for solving Maxwell's equations for light scattering from particles of arbitrary shape in a complex environment. Included is a description of the qualitative features of dipole and quadrupole plasmon resonances for spherical particles; a discussion of analytical and numerical methods for calculating extinction and scattering cross-sections, local fields, and other optical properties for nonspherical particles; and a survey of applications to problems of recent interest involving triangula...

9,086 citations

Journal ArticleDOI
TL;DR: This review discusses the synthetic chemistry, fluid stabilization and surface modification of superparamagnetic iron oxide nanoparticles, as well as their use for above biomedical applications.

6,207 citations

Journal ArticleDOI
15 Aug 1996-Nature
TL;DR: A method for assembling colloidal gold nanoparticles rationally and reversibly into macroscopic aggregates by using the specificity of DNA interactions to direct the interactions between particles of different size and composition is described.
Abstract: COLLOIDAL particles of metals and semiconductors have potentially useful optical, optoelectronic and material properties1–4 that derive from their small (nanoscopic) size. These properties might lead to applications including chemical sensors, spectro-scopic enhancers, quantum dot and nanostructure fabrication, and microimaging methods2–4. A great deal of control can now be exercised over the chemical composition, size and polydis-persity1,2 of colloidal particles, and many methods have been developed for assembling them into useful aggregates and materials. Here we describe a method for assembling colloidal gold nanoparticles rationally and reversibly into macroscopic aggregates. The method involves attaching to the surfaces of two batches of 13-nm gold particles non-complementary DNA oligo-nucleotides capped with thiol groups, which bind to gold. When we add to the solution an oligonucleotide duplex with 'sticky ends' that are complementary to the two grafted sequences, the nanoparticles self-assemble into aggregates. This assembly process can be reversed by thermal denaturation. This strategy should now make it possible to tailor the optical, electronic and structural properties of the colloidal aggregates by using the specificity of DNA interactions to direct the interactions between particles of different size and composition.

6,188 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
202312,333
202225,747
20214,225
20204,551
20194,882