An optical microtoroid resonator including one or more nanoparticles attached to a surface of the resonator and capable of receiving an input signal from afar-field source (via free-space transmission) and outputting light propagating within the optical apparatus. A method for coupling light into and out of an optical resonator using a nanoparticle or nanoparticles to interface with spatially separated far-field optical elements.

An integrated optofluidic system for trapping and transporting particles for analysis is provided comprising a planar substrate; a microfluidic channel; and a waveguide integrated with the channel. A microsphere particle in the integrated optofluidic system can act as a cavity, allowing light to circulate many thousands of times around the circumference of the microsphere. Optical trapping and transport is used for nanoscale positioning to excite the microsphere resonances. Sensitive measurements on molecules can be accomplished by monitoring changes in whispering gallery modes (WGMs) that propagate around the circumference of the microsphere. By using a broadband or supercontinuum light source, a microsphere can be trapped and many WGM resonances can be excited through the visible and near-infrared wavelengths simultaneously. After the resonances are measured using the waveguide transmission, the microsphere can be freed by decreasing the optical power and the process repeated with a different microsphere.

Disclosed are a method and a device for the marker-free detection of an analyte in a fluid. At least one dielectric microsensor is used, which comprises a microresonator and an adsorbate layer for binding an analyte, which adsorbate layer is applied to the microresonator. The microresonator consists of a particle which comprises a dielectric material and a fluorescent marker. Furthermore, the microresonator has an optical refractive index that is higher than the optical refractive index of a fluid to be analyzed. The microresonator is suitable for allowing more than one resonance mode to form in the interior thereof when the fluorescent marker is excited. The optical thickness of the adsorbate layer of the microsensor is determined from spectral positions of at least two detected optical resonance modes of the microsensor and used to determine the extent to which an analyte has bonded to the at least one microsensor.

Optical analytical devices and their methods of use are provided. The devices are useful in the analysis of highly multiplexed optical reactions in large numbers at high densities, including biochemical reactions, such as nucleic acid sequencing reactions. The devices include integrated illumination elements and optical waveguides for illumination of the optical reactions. The devices further provide for the efficient coupling of optical excitation energy from the waveguides to the optical reactions. Optical signals emitted from the reactions can thus be measured with high sensitivity and discrimination using features such as spectra, amplitude, and time resolution, or combinations thereof. The devices of the invention are well suited for miniaturization and high throughput.

A corrosion detecting composition comprising a nanoparticle and at least one chemically reactive adsorbate associated with the nanoparticle. The chemically reactive adsorbate displays a responsive surface enhanced Raman scattering (SERS) spectral response that is a function of pH. The nanoparticle is contained in a selective carrier; such that the selective carrier allows transport of protons or hydroxide anions to the chemically reactive adsorbate associated with the nanoparticle. Lastly, the selective carrier restricts transport of organic chemical compounds to the at least one chemically reactive adsorbate. This allows the Raman sensor molecules to be blended with paints and coatings prior to application on metal surfaces, and the Raman sensor molecules do not prematurely react with the components of paints or coatings. A Raman detectors can be used to non-destructively interrogate the Raman sensor molecules and detect the pH changes associated with undercoat corrosion.

A detector (100) for surface-enhanced infrared absorption spectroscopy comprises resonators which are distributed over a surface (S) of a support (1), said surface being intended to receive a sample (101) to be tested. The resonators are able to provoke a spectral reflectance of at least 40% for electromagnetic radiation that is incident on the surface of the support, in the absence of a sample, and when the radiation is at the resonance wavelength value of the resonators. The detector has high sensitivity to small amounts of a target molecule.

The invention relates to an optical sensor for detecting Caesium ions and/or measuring concentration of the same in a fluid medium, comprising a resonant structure (1), a surface of which is covered by a layer of a macrocyclic compound (2). The invention further relates to a method for covering a surface of a resonant structure (1) of an optical sensor with a layer of a macrocyclic compound (2) such that the optical sensor is capable of detecting Caesium ions and/or measuring concentration of the same in a fluid medium.