Methods for screening skin cleansers for mildness can include utilization of a volume ratio of vesicles to micelles.

A system that monitors particle motion behavior for point-of-care diagnostics is described. The system can include a sample testing unit configured to house a sample. The sample testing unit can include a plurality of motor structures configured for self-propulsion based on a presence or an absence of a target analyte in the sample and a plurality of beads configured to experience a motion behavior based on the self-propulsion of the plurality of motor structures. Each of the plurality of motor structures can include a catalytic motor-like micro/nanoparticle; and an attached functional material specific for the target analyte attached to the catalytic motor-like particle. The optical recording unit can include an optical arrangement configured to detect the motion behavior of the beads in the sample testing unit. The motion behavior can be indicative of the presence or the absence of the target analyte.

According to one aspect, the subject of the present description is a device (100) for determining characteristic parameters of the dimensions of nanoparticles in suspension in a liquid. The device (100) comprises light-emitting means (101) configured to emit an incident light beam (B.sub.i) that is linearly polarized along a polarization axis (P.sub.1); a detecting unit (102) comprising a measurement arm (120) that is rotatable with respect to an axis of rotation (), said detecting unit comprising first and second detection channels (151, 161) that are separated by a polarization-splitting element (125) arranged in said measurement arm; a fixed sample holder (103), configured to receive a container (10) of cylindrical symmetry of said sample, an axis of symmetry of the container being coincident with the axis of rotation of the measurement arm; and a control unit (104). The polarization-splitting element (125) of the measurement arm is configured to simultaneously send, over each of the first and second detection channels, respectively, a first and second polarized component (B.sub.S1, B.sub.S2) of the beam (B.sub.S) scattered by the sample, the polarization axes of the first and second polarized components being perpendicular.

The control unit (104) is configured to determine, from signals corresponding to the polarized components detected in each of the detection channels as a function of time, at least two characteristic parameters of the dimensions of the nanoparticles.

Speckle contrast method and system that discriminates photons based on their path length in tissue, the method comprising the steps of: directing light from a pulsed light into a sample by optical elements; synchronizing the time between the pulse injection to sample and the detection unit; collecting the photons that have travelled through the sample by optics, and conveying the photons of a single or a limited number of speckles from the sample to one or more detection elements; time-tagging photons thanks to the synchronization of the detector element and/or the time-tagging electronics with the laser pulse emission; estimating each photon time-of-flight by the difference between its time tag and the laser pulse emission; categorizing the detected photons based on the value of the time-of-flight in a certain number of time gates; measuring the speckle contrast.

The present disclosure describes a method and apparatus of measuring dynamic light scattering of a sample. In an embodiment, the apparatus includes a platen, a light source underneath the platen and configured to emit emitted light through the platen and into the sample, collector optics underneath the platen and configured to capture scattered light, and an optical absorber configured to be in contact with the sample, configured to absorb transmitted light, and configured to redirect reflected light away from the collector optics. In an embodiment, the method includes depositing a sample on a platen, emitting emitted light from a light source underneath the platen through the platen and into the sample, capturing via collector optics underneath the platen scattered light, contacting the sample with an optical absorber, absorbing via the absorber transmitted light, and redirecting via the absorber reflected light away from the collector optics.

Provided herein are particle detection systems, and related methods configured to characterize a liquid sample, comprising: a first probe configured to determine a first parameter set of a plurality of first particles in a liquid sample, the first particles characterized by a size characteristic selected from a first size range; wherein the first parameter set comprises a first size distribution and a first concentration; and a second probe configured to determine a second parameter set of one or more second particles in the liquid sample, the second particles being characterized by a size characteristic selected from a second size range; wherein the second parameter set comprises a second size distribution and a second concentration.

To enable the particle size distribution of a measurement target to be accurately measured regardless of the presence of a particle which is similar in shape to the measurement target and which is not the measurement target, a particle size distribution measuring device includes an image processing unit that receives image data obtained by capturing an image of a particle group including a first particle and a second particle of a type different from the first particle, at least the first particle being translucent; and a particle discriminating unit that discriminates whether a particle depicted in the image is the first particle or the second particle on the basis of light and dark regions that appear as a result of refraction of light passing through the particle.

A particle characterisation apparatus comprising: a light source for illuminating a sample with a light beam; a detector arranged to detect scattered light from the interaction of the light beam with the sample; a focus tuneable lens arranged to collect the scattered light for the detector from a scattering volume and/or to direct the light beam into the sample, a sample holder with an opposed pair of electrodes and configured to hold a sample in position in a measurement volume between the pair of electrodes such that a planar surface of the sample is aligned orthogonally to the electrode surfaces, the planar surface adjacent to the scattering volume, wherein adjustment of the focus tuneable lens results in adjustment of the relative position of the planar surface and the scattering volume by moving the scattering volume.

A method and apparatus are disclosed for the collection of light scattered from a liquid sample contained within a multiwell plate for which evaporation from the wells is mitigated by the application of a barrier between the liquid sample and the environment. A vertical thermal gradient is applied across the vessel so that condensation is inhibited from forming on the interior surface of the barrier, thus permitting clear illumination of the sample for visual imaging, fluorescence studies and light scattering detection.

A method for monitoring a property of nanoparticles in a flowing suspension comprises providing a sample comprising a flowing suspension. The method further comprises non-invasively monitoring a size distribution of nanoparticles of the flowing suspension using

Fourier domain low-coherence interferometry, FDLCI, wherein the monitoring comprises deriving a time and optical path length resolved LCI light scattering signal l(t,z) from time resolved LCI wavelength spectra of interference and deriving information indicative of the size of the particles in the sample based on said time and optical path length resolved LCI light scattering signal using optical path length resolved temporal autocorrelation functions or optical path length resolved frequency power spectra of the spatiotemporal FDLCI signal.