Thermophoresis measurements in nanoliter-droplets

摘要

The present invention relates generally to a system and a method for thermo-optical measurements in a droplet (23) of aqueous solution comprising particles of interest, the method comprising the following steps: providing the droplet of aqueous solution with a volume of less than 200nl, wherein the aqueous solution is a first liquid (21) and at least a part of the particles of interest are fluorescent particles; embedding the droplet (23) of aqueous solution at least partly in a second liquid (21); irradiating a laser light beam into the droplet to obtain a spatial temperature distribution in the droplet around the irradiated laser light beam; exciting fluorescently said fluorescent particles and detecting the fluorescence at least at one position or at around one position in the droplet or detecting the fluorescence distribution of said fluorescently excited particles, wherein said detection of fluorescence is performed at least once at a predetermined time after the start of the laser irradiation; and determining a characteristic of the particles of interest from the detected fluorescence intensity or fluorescence intensity distribution.