METHOD AND DEVICE FOR OPTICALLY DETECTING NANOPARTICLES IN A FLUID SAMPLE

摘要

According to one aspect, the invention relates to a device (100) for optically detecting in transmission nanoparticles moving in a fluid sample, comprising: a light source (10) for emitting a spatially incoherent beam for illuminating the sample; an imaging optical system (30) comprising a microscope objective (31); a two-dimensional optical detector (40) comprising a detection plane (41) conjugated with an object focal plane of the microscope objective by said imaging optical system (30), and allowing a sequence of images of an analysis volume of the sample to be acquired, each image resulting from optical interference between the illuminating beam incident on the sample and the beams scattered by each of the nanoparticles present in the analysis volume during a preset duration shorter than one millisecond; and image-processing means (50) allowing an average of a sequence of said images to be taken and said average to be subtracted from each image in order to determine, for each nanoparticle of the analysis volume, the amplitude of the scattered beam.