Assays used in conjunction with a thermal contrast reader are disclosed. In the assay, the test strip includes materials that can develop a thermal response if a target analyte is present in a sample. Linear flow assays include nanoparticles with high affinity binding to the analyte. Binding of the nanoparticles with an analyte in the sample is detected using thermal contrast. Analytes over a broad range of concentrations are detected in the linear flow assays. Methods of detecting target analytes and kits comprising lateral flow assays and thermal contrast reader are also disclosed.

Mid-infrared photothermal heterodyne imaging (MIR-PHI) techniques described herein overcome the diffraction limit of traditional MIR imaging and uses visible photodiodes as detectors. MIR-PHI experiments are shown that achieve high sensitivity, sub-diffraction limit spatial resolution, and high acquisition speed. Sensitive, affordable, and widely applicable, photothermal imaging techniques described herein can serve as a useful imaging tool for biological systems and other submicron-scale applications.

A method and an interferometric device for spectroscopically or spectrometrically examining a sample, comprising: a) generating a laser beam having a wavelength, b) splitting the laser beam into a measurement beam and a reference beam, c) interacting the sample with the measurement beam, d) interacting a reference with the reference beam, e) overlaying the measurement beam and the reference beam, f) detecting a first output beam, g) detecting a second output beam, h) forming a differential signal between the first output signal and the second output signal, i) controlling the differential signal to a predefined target value, j) determining a refractive index of the sample from the adjustment of the phase difference between the measurement beam and the reference beam, k) repeating steps a) to j) for additional wavelengths of the laser beam.

A method and system for detecting moisture in a composite sandwich panel for an aerospace vehicle. A pulse of an electromagnetic radiation beam is beam steered to the composite sandwich panel. The pulse of the electromagnetic radiation beam has a number of wavelengths that is absorbed by water molecules. The timing of the pulse of the electromagnetic radiation beam is synchronized to heat the composite sandwich panel with a time window in an infrared detector system to detect an amount of infrared radiation. The amount of infrared radiation in the composite sandwich panel is detected within the time window for the infrared detector system when the composite sandwich panel is heated by the pulse of the electromagnetic radiation beam, wherein the amount of infrared radiation indicates a level of moisture in the composite sandwich panel.

A photothermal deflection measuring system includes a substrate, a detecting light source, a detecting unit, and a processor. The substrate includes a plurality of positioning structures, on each of which supports a cell emitting heat outside a surface thereof. The detecting light source is utilized to project a detecting light passing through a specific position outside the surface whereby the detecting light is deflected due to a thermal gradient caused by the emitted heat. The detecting unit is arranged at a side of the cell for receiving the deflected detecting light thereby generating an optical deflection signal corresponding to a deflection of the deflected detecting light. The processor is configured to receive the optical deflection signal, analyze the optical deflection signal and determine a heat value corresponding to the specific position out side the surface of the cell according to the optical deflection signal.

A photothermal absorbance detection apparatus comprises a flow cell comprising a first temperature responsive device on an input side, a second temperature responsive device on an output side, and a detection region between the first temperature responsive device and the second temperature responsive device; and a light-emitting device positioned proximate to the detection region and configured to transmit electromagnetic radiation towards the detection region; wherein the first temperature responsive device and the second temperature responsive device together measure a change in temperature of a fluid passing through the detection region.

System for performing chemical spectroscopy on samples from the scale of nanometers to millimeters or more with a multifunctional platform combining analytical and imaging techniques including dual beam photo-thermal spectroscopy with confocal microscopy, Raman spectroscopy, fluorescence detection, various vacuum analytical techniques and/or mass spectrometry. In embodiments described herein, the light beams of a dual-beam system are used for heating and sensing.

Provided is a gas concentration length measurement device into which image data (moving image data) representing a plurality of infrared images is input, the image data being obtained by taking infrared images of a gas leakage monitoring target at a plurality of times. The gas concentration length measurement device generates chronological pixel data in which pieces of pixel data for pixels that are at the same positions in the plurality of infrared images are arranged chronologically, then uses the chronological pixel data for a predetermined pixel among the plurality of pixels constituting the infrared images as a basis to determine a with-gas background temperature indicating the background temperature when a gas is present in a predetermined region corresponding to the predetermined pixel and a without-gas background temperature indicating the background temperature when gas is not present in the predetermined region.

A system and method for photo-thermal imaging of a lateral flow immunoassay (LFA) device are provided. The system includes an intensity modulated heat source directed at a surface of the LFA device to selectively excite chromophore particles of interest and a thermal capture device configured to capture thermal waves emitted from the surface of the LFA device as a radiometric signal. A computing device, in communication with the thermal capture device, receives the radiometric signal and executes lock-in demodulation to detect surface or subsurface inhomogeneities of the LFA device.

A method and system for detecting moisture in a composite sandwich panel for an aerospace vehicle. A pulse of an electromagnetic radiation beam is beam steered to the composite sandwich panel. The pulse of the electromagnetic radiation beam has a number of wavelengths that is absorbed by water molecules. The timing of the pulse of the electromagnetic radiation beam is synchronized to heat the composite sandwich panel with a time window in an infrared detector system to detect an amount of infrared radiation. The amount of infrared radiation in the composite sandwich panel is detected within the time window for the infrared detector system when the composite sandwich panel is heated by the pulse of the electromagnetic radiation beam, wherein the amount of infrared radiation indicates a level of moisture in the composite sandwich panel.