Abstract: This invention relates to a method for measuring viscosity of a fluid using particle diffusometry (PD). The method finds practical applications in detecting structural and functional changes of a biomolecular composition by comparing the viscosity change as compared with the standard of the biomolecular composition. This method may also find uses in clinical diagnosis and quality control of clinical biological medicines, food and feeds during the process of manufacturing, distribution and consumption.

Abstract: Methods and systems suitable for tracking Brownian motion of particles suspended in a fluid and determining the diffusion coefficient of the particles therefrom in order to characterize the particles, their synthesis, and/or their surface modifications. The methods include providing a sample having particles suspended in a fluid, obtaining and recording at least first and second images of the sample wherein the first image obtained at a first time and the second image subsequently obtained at a second time, determining the average displacement of the particles in an area of the first and second images during a time period between the first time and the second time based on the first and second images, and then determining a diffusion coefficient of the particles in the area of the first and second images based on the average displacement of the particles during the time period.

Abstract: A particle sensing system which includes a plurality of micro-lenses which focus light from an unfocused or loosely focused light source onto a corresponding plurality of focus regions on a surface containing plasmonic structures. The absorption of light by the plasmonic structures in the focus regions results in heat dissipation in the plasmonic structures and consequently increases surface temperature in the focus regions. When an electrical field is applied to a sample fluid in contact with the surface, multiple electrothermal flows are induced in the fluid which rapidly transport suspended particles to the focus regions on the surface. The particles can then be captured and/or sensed.

Abstract: This invention relates to a method for measuring viscosity of a fluid using particle diffusometry (PD). The method finds practical applications in detecting structural and functional changes of a biomolecular composition by comparing the viscosity change as compared with the standard of the biomolecular composition. This method may also find uses in clinical diagnosis and quality control of clinical biological medicines, food and feeds during the process of manufacturing, distribution and consumption.

Abstract: A system and method suitable for selection, manipulation, and analysis of individual particles within a fluid medium. The system and method involve manipulating the particles by contacting the fluid medium with a plasmonic nanoantenna, illuminating the plasmonic nanoantenna with a source of light such that the plasmonic nanoantenna acts as a nanoscale heat source resulting in localized heating of the fluid medium creating local gradients in the electrical properties of the fluid medium that yield plasmonic trapping sites in the vicinity of the plasmonic nanoantenna, and applying an alternating current electric field in the fluid medium to create electrothermoplasmonic flow around the plasmonic nanoantenna. The electrothermoplasmonic flow transports at least one of the particles towards the plasmonic nanoantenna and the particle is trapped by at least one of the plasmonic trapping sites.

Abstract: A system and method suitable for selection, manipulation, and analysis of individual particles within a fluid medium. The system and method involve manipulating the particles by contacting the fluid medium with a plasmonic nanoantenna, illuminating the plasmonic nanoantenna with a source of light such that the plasmonic nanoantenna acts as a nanoscale heat source resulting in localized heating of the fluid medium creating local gradients in the electrical properties of the fluid medium that yield plasmonic trapping sites in the vicinity of the plasmonic nanoantenna, and applying an alternating current electric field in the fluid medium to create electrothermoplasmonic flow around the plasmonic nanoantenna. The electrothermoplasmonic flow transports at least one of the particles towards the plasmonic nanoantenna and the particle is trapped by at least one of the plasmonic trapping sites.