摘要:
A system and method for free space, optical remote sensing of a potential threat agent using spectrally responsive sensor material. In one example the sensor material is formed by particles, which in one particular form are porous photonic crystals. The particles are dispersed into an area being monitored for the presence of the potential threat agent. A pair of lasers is used to generate optical light beams that are directed at the sensor particles after the particles have been dispersed. The light reflected by the sensor particles is then analyzed. The presence of the potential threat agent causes a shift in the spectral peak of light reflected from the sensor particles that can be sensed using photo detectors and a processing subsystem. The system can be tuned to remotely detect for specific chemical, biological or environmental agents that may be present within a given area.
摘要:
A system and method for free space, optical remote sensing of a potential threat agent using spectrally responsive sensor material. In one example the sensor material is formed by particles, which in one particular form are porous photonic crystals. The particles are dispersed into an area being monitored for the presence of the potential threat agent. A pair of lasers is used to generate optical light beams that are directed at the sensor particles after the particles have been dispersed. The light reflected by the sensor particles is then analyzed. The presence of the potential threat agent causes a shift in the spectral peak of light reflected from the sensor particles that can be sensed using photo detectors and a processing subsystem. The system can be tuned to remotely detect for specific chemical, biological or environmental agents that may be present within a given area.
摘要:
A method of generating three-dimensional nanostructures that includes providing a silicon substrate, creating a porous silicon template from the silicon substrate, wherein the template is created to have a predetermined configuration, depositing a predetermined material on the porous silicon template, and removing the porous silicon template from the deposited material to leave a freestanding nanostructure.
摘要:
The invention is related to optical particles (10), use of optical particles in sensing applications, and methods of fabricating optical particles that can target a desired analyte. The invention is also related to the self assembly of individual optical particles. An advantage of the invention is that it includes self-assembling individual photonic crystal sensors onto a target. In an embodiment of the invention, a processed sensor structure having two generally opposing surfaces is provided, wherein each of the opposing surfaces have different surface affinities, with a first optical structure formed on one of the opposing surfaces, and a second optical structure formed on the other of the opposing surfaces. The chemically and optically asymmetric opposing surfaces will spontaneously align at an organic liquid/water interface. Changes in the optical response of at least one of the opposing surfaces indicate the presence of a particular analyte for sensing applications.
摘要:
Methods and systems of the invention can determine the identity and quantity of analytes in a vapor. In preferred methods, a porous optical film is exposed to vapor which contains analyte. The porous optical film is heated and its optical response is monitored during heating. An optical response observed via heating can determine the identity and/or quantity of the analyte. In preferred embodiments, optical response during a thermal pulse is compared to a database of sensor responses that are characteristic of various analytes. Preferred methods are conducted a relatively low temperatures, for example below about 200° C. In preferred methods, a heating and cooling cycle produces a hysteresis curve in the optical response that is indicative of analytes. In preferred embodiments, a thermal reset pulse resets the porous optical film for later use and also provides an optical response that can be used for sensing.
摘要:
The present invention uses externally applied electromagnetic stimulus to control and heat porous magnetic particles and material associated with the particles. The particles contain magnetic material, such as superparamagnetic iron oxide and are infused with a material. Application of a DC magnetic field allows them to be moved with their infused material, and application of an AC RF electromagnetic field allows them to be heated with their infused material. The material can be infused into pores of the particles and the particles can also adhere to an aqueous droplet. The present invention also provides a multi-layer porous magnetic particle. The particle includes a host layer having pores sized to accept magnetic nanoparticles. Magnetic nanoparticles are infused within pores of the host layer. An encoding layer includes pores that define a spectral code. The pores in the encoding layer are sized to substantially exclude the magnetic nanoparticles. The encoding layer can also be a multi-layer, exhibiting, for example, a complex spectral code.
摘要:
A method for forming photonic particles, where the method includes the steps of preparing a porous photonic material layer, patterning a soluble polymer on the porous photonic material layer, leaving dividing portions of the material layer untreated, infusing the polymer into the material layer, and removing the dividing portions of the material to obtain the photonic particles.
摘要:
The measurement of the wavelength shifts in the reflectometric interference spectra of a porous semiconductor substrate such as silicon, make possible the highly sensitive detection, identification and quantification of small analyte molecules. The sensor of the subject invention is effective in detecting multiple layers of biomolecular interactions, termed “cascade sensing”, including sensitive detection of small molecule recognition events that take place relatively far from the semiconductor surface.
摘要:
A method for imaging leverages the fluorescence lifetime of a fluorescent Si-containing particle to distinguish from background fluorescence. A particle is introduced into tissue. An excitation light pulse is applied to excite luminescence from the fluorescent Si-containing particle. Time-gated measuring of a responsive luminescence signal identifies the particle. In preferred embodiments the particle is coated or encapsulated with an organic material. The fluorescence lifetime of particles can be controlled during manufacture, such as by oxidation levels, quenching treatments, or by aging. This permits introducing and using groups of particles in imaging that have unique lifetimes and multiple time gating can be used to identify different particles or to monitor the change in lifetime of a single set of particles as they respond to a biochemical stimulus. The particles can also be functionalized for affinity to particular tissues and can be loaded with treatment molecules.
摘要:
The invention provides a porous sensor and sensing methods that use a porous sensor with a porous nanostructure having an optical response and having a portion of the porous nanostructure filled with a fiducial marker that is non-reactive to an analyte of interest. In a preferred sensing method, reflectance spectra from both the fiducial marker and reactive portions of the porous structure are acquired simultaneously. The fiducial marker provides an internal reference that permits compensation for humidity, as well as off angle measurements. In addition, simple visual observations can reveal the presence of an analyte, including human observations.