Abstract: A substrate for enhanced electromagnetic spectroscopy of an analyte comprises a solid support and a plurality of individual nanoparticles affixed thereto, wherein the nanoparticles are designed to have an increased electromagnetic field strength and/or plasmon resonance frequency that is between the frequency of an incident electromagnetic radiation and the frequency of the Raman response from the analyte and wherein the Raman response is enhanced by the individual nanoparticles. The nanoparticles may comprise a shell surrounding a core and the thicknesses of the core and the shell are selected to produce a plasmon resonance frequency. The wavelength of the incident radiation may be between 200 nm and 20 microns. A method for carrying out spectroscopy comprises providing a light source having a frequency different from that of the analyte, selecting a nanoshell configuration, providing a plurality of nanoshells with that configuration, and affixing the nanoparticles to a support.

Abstract: A composition comprising a nanoparticle and at least one adsorbate associated with the nanoparticle, wherein the adsorbate displays at least one chemically responsive optical property. A method comprising associating an adsorbate with a nanoparticle, wherein the nanoparticle comprises a shell surrounding a core material with a lower conductivity than the shell material and the adsorbate displays at least one chemically responsive optical property, and engineering the nanoparticle to enhance the optical property of the adsorbate. A method comprising determining an optical response of an adsorbate associated with a nanoparticle as a function of a chemical parameter, and parameterizing the optical response to produce a one-dimensional representation of at least a portion of a spectral window of the optical response in a high dimensional vector space.

Abstract: The present invention is for particulate compositions and methods for producing them that can absorb or scatter electromagnetic radiation. The particles are homogeneous in size and are comprised of a nonconducting inner layer that is surrounded by an electrically conducting material. The ratio of the thickness of the nonconducting layer to the thickness of the outer conducting shell is determinative of the wavelength of maximum absorbance or scattering of the particle. Unique solution phase methods for synthesizing the particles involve linking clusters of the conducting atoms, ions, or molecules to the nonconducting inner layer by linear molecules. This step can be followed by growth of the metal onto the clusters to form a coherent conducting shell that encapsulates the core.

Abstract: Composite particles containing metallic shell layers are provided. The particles may include a coating layer, such as of a protective or electrically non-conducting material, over an outermost metallic shell layer. The particle preferably has a plasmon resonance associated with at least one metallic shell layer. The coating layer preferably imparts improved thermal stability to the plasmon resonance. Further, the present invention relates to particles that include at least two metallic shell layers, separated by a coating layer. The addition of a second metallic shell layer preferably allows the plasmon resonance of the shell layer to be more red-shifted with respect to a colloidal particle of the metal that the plasmon resonance of a particle of the same size but with only a single metallic shell.

Abstract: A method for purifying a suspension containing colloid-seeded nanoparticles and excess colloids is provided that includes adding to the suspension a filter aid comprising a salt. The method further includes filtering the suspension with a filter of a pore size intermediate between the average colloid-seeded nanoparticle size and the average excess colloid size, so as to form a retentate that includes the majority of the colloid-seeded nanoparticles and a filtrate that includes the majority of the excess colloids. Still further, the method includes collecting the retentate. The method may be incorporated into a method of making metallized nanoparticles, such as nanoshells, by reduction of metal ions onto the purified colloid-seed nanoparticles so as to form the metallized nanoparticles.

Abstract: The present invention relates to incorporating metal nanoshells specifically designed to interact with triplet excitons in polymers. By interacting with triplet excitons, the rate of photo-oxidation can be slowed and the density of luminescence-quenching traps can be reduced.

Abstract: The present invention is for particulate compositions and methods for producing them that can absorb or scatter electromagnetic radiation. The particles are homogeneous in size and are comprised of a nonconducting inner layer that is surrounded by an electrically conducting material. The ratio of the thickness of the nonconducting layer to the thickness of the outer conducting shell is determinative of the wavelength of maximum absorbance or scattering of the particle. Unique solution phase methods for synthesizing the particles involve linking clusters of the conducting atoms, ions, or molecules to the nonconducting inner layer by linear molecules. This step can be followed by growth of the metal onto the clusters to form a coherent conducting shell that encapsulates the core.

Abstract: The present invention provides a sensor that includes an optical device as a support for a thin film formed by a matrix containing resonant nanoparticles. The nanoparticles may be optically coupled to the optical device by virtue of the geometry of placement of the thin film. Further, the nanoparticles are adapted to resonantly enhance the spectral signature of analytes located near the surfaces of the nanoparticles. Thus, via the nanoparticles, the optical device is addressable so as to detect a measurable property of a sample in contact with the sensor. The sensors include chemical sensors and thermal sensors. The optical devices include reflective devices and waveguide devices. Still further, the nanoparticles include solid metal particles and metal nanoshells. Yet further, the nanoparticles may be part of a nano-structure that further includes nanotubes.

Abstract: The present invention provides nanoshell particles (“nanoshells”) for use in biosensing applications, along with their manner of making and methods of using the nanoshells for in vitro and in vivo detection of chemical and biological analytes, preferably by surface enhanced Raman light scattering. The preferred particles have a non-conducting core and a metal shell surrounding the core. For given core and shell materials, the ratio of the thickness (i.e., radius) of the core to the thickness of the metal shell is determinative of the wavelength of maximum absorbance of the particle. By controlling the relative core and shell thicknesses, biosensing metal nanoshells are fabricated which absorb light at any desired wavelength across the ultraviolet to infrared range of the electromagnetic spectrum. The surface of the particles are capable of inducing an enhanced SERS signal that is characteristic of an analyte of interest.

Abstract: This invention is generally in the field of improved methods for the localized delivery of heat and the use thereof for the repair of tissue. The method involves localized induction of hyperthermia in tissue or materials by delivering nanoparticles to the tissue or materials and exposing the nanoparticles to an excitation source under conditions wherein they emit heat. The generation of heat effects the joining of the tissue or materials.

Abstract: The present invention is for particulate compositions and methods for producing them that can absorb or scatter electromagnetic radiation. The particles are homogeneous in size and are comprised of a nonconducting inner layer that is surrounded by an electrically conducting material. The ratio of the thickness of the nonconducting layer to the thickness of the outer conducting shell is determinative of the wavelength of maximum absorbance or scattering of the particle. Unique solution phase methods for synthesizing the particles involve linking clusters of the conducting atoms, ions, or molecules to the nonconducting inner layer by linear molecules. This step can be followed by growth of the metal onto the clusters to form a coherent conducting shell that encapsulates the core.

Abstract: This process results in directed electroless plating of the metal to form discrete metal structures over the entire surface. Because the surface is pre-patterned with passivated regions inert to metal deposition, the metal is directed only to the unstamped regions. This allows the formation of unconnected metal structures without any chemical etching steps. These metallic arrays are varied in size, separation and shape by using gratings of different periodicities and blaze angles as the stamp templates. A variety of well-defined geometric patterns have been fabricated and imaged using scanning probe, scanning electron, and optical microscopies.

Abstract: Metal Nanoshells having partial coverage of a substrate or core particle and methods of making them are provided. A method of making a partial metal nanoshell preferably includes asymmetrically confining a substrate particle and selectively layering a metallic material over the substrate particle according to the asymmetry. Confining the substrate particle may include attaching it to a support defining an exposed portion and a contact portion. The method may include either chemically modifying the substrate particle. The solid angle of coverage of the partial metal nanoshell may be influenced by the nature of the chemical modification, such as alternatives of activating and passivating the exposed portion.

Abstract: Methods and apparatus for providing nanoparticles having reduced symmetry are disclosed. One embodiment of a preferred method for producing such nanoparticles includes functionalization of a nanoparticle core, partial chemical passivation or masking of the nanoparticle surface, and nucleation and deposition of colloidal particles to selectively coat a specific section of the nanostructure surface with a conducting material.

Abstract: A thermally sensitive polymer-particle composite that absorbs electromagnetic radiation, and uses the absorbed energy to trigger the delivery of a chemical is disclosed. Metal nanoshells are nanoparticulate materials that are suitable for use in the present composites and can be made according to a process that includes optically tuning or tailoring their maximum optical absorption to any desired wavelength primarily by altering the ratio of the core diameter to the shell thickness. Preferred nanoshells are selected that strongly absorb light in the near-infrared and thus produce heat. These nanoshells are combined with a temperature-sensitive material to provide an implantable or injectable material for modulated drug delivery via external exposure to near-IR light. This invention provides a means to improve the quality of life for persons requiring multiple injections of a drug, such as diabetes mellitus patients.

Abstract: The present invention provides a sensor that includes an optical device as a support for a thin film formed by a matrix containing resonant nanoparticles. The nanoparticles may be optically coupled to the optical device by virtue of the geometry of placement of the thin film. Further, the nanoparticles are adapted to resonantly enhance the spectral signature of analytes located near the surfaces of the nanoparticles. Thus, via the nanoparticles, the optical device is addressable so as to detect a measurable property of a sample in contact with the sensor. The sensors include chemical sensors and thermal sensors. The optical devices include reflective devices and waveguide devices. Still further, the nanoparticles include solid metal particles and metal nanoshells. Yet further, the nanoparticles may be part of a nano-structure that further includes nanotubes.

Abstract: A method for purifying a suspension containing colloid-seeded nanoparticles and excess colloids is provided that includes adding to the suspension a filter aid comprising a salt. The method further includes filtering the suspension with a filter of a pore size intermediate between the average colloid-seeded nanoparticle size and the average excess colloid size, so as to form a retentate that includes the majority of the colloid-seeded nanoparticles and a filtrate that includes the majority of the excess colloids. Still further, the method includes collecting the retentate. The method may be incorporated into a method of making metallized nanoparticles, such as nanoshells, by reduction of metal ions onto the purified colloid-seed nanoparticles so as to form the metallized nanoparticles.

Abstract: The present invention provides a photoactuator comprising a plurality of nanoparticles and a thermally sensitive material. The photoactuator is useful for a variety of applications including macroscale and nanoscale applications. The nanoparticles are in thermal contact with the thermally sensitive material. The nanoparticles are engineered to achieve peak resonance at a given wavelength of light such that upon illumination. Upon illumination of the thermally sensitive material, the nanoparticles convert the light to heat, which is transferred to the thermally sensitive material, inducing a change in volume in the thermally sensitive material. The present invention is useful for actuating devices, especially in microfluidic devices. Methods for making a photoactuator and various embodiments thereof are also provided.

Abstract: This invention is generally in the field of improved methods for the localized delivery of heat and the use thereof for the repair of tissue. The method involves localized induction of hyperthermia in tissue or materials by delivering nanoparticles to the tissue or materials and exposing the nanoparticles to an excitation source under conditions wherein they emit heat. The generation of heat effects the joining of the tissue or materials.

Abstract: This invention is generally in the field of improved methods for the localized delivery of heat and the localized imaging of biological materials. The delivery may be in vitro or in vivo and is useful for the localized treatment of cancer, inflammation or other disorders involving overproliferation of tissue. The method is also useful for diagnostic imaging. The method involves localized induction of hyperthermia in a cell or tissue by delivering nanoparticles to said cell or tissue and exposing the nanoparticles to an excitation source under conditions wherein they emit heat.