A detection method for single nanoparticles

Abstract

The invention relates to a detection method for a single nanoparticle. The detection method comprises the following steps: attaching a single nanoparticle on a cover glass; focusing the light emitted by a light source on the back focal plane of an oil immersion objective lens after beam expansion and shaping; Adjust the position of the incident light on the back focal plane of the oil immersion objective lens, so that the incident light is obliquely incident on the cover glass, and the surface of the cover glass propagates along the surface, and the intensity decays exponentially in the vertical direction The evanescent wave; the evanescent wave encounters the single nanoparticle and scatters, and propagates along the surface of the cover glass to generate radial interface scattering; the signal scattered by the interface and the signal on the cover glass are collected by the CCD Light is reflected and the individual nanoparticles are imaged by the CCD. The invention has the advantages of low cost, stable detection performance, fast detection speed and high sensitivity, can be used for in-situ and portable detection, and can be extended to applications such as virus detection and nano pollutants in the atmosphere.

Description

technical field [0001] The invention relates to the technical field of microscopic imaging detection, in particular to a detection method for a single nanoparticle. Background technique [0002] In recent years, with the development of nano, material, and optical technologies, nanoscale microscopic imaging has been widely used in life sciences, biochemistry, materials science, etc. and other fields. [0003] Among the currently widely used imaging technologies, ordinary optical microscopes are limited by the diffraction limit and have low resolution, so they cannot detect substances with a size smaller than 200nm. Electron microscopy, including transmission electron microscopy (TEM) and scanning electron microscopy (SEM), can improve resolution to the nanometer level. However, electron microscopy requires a vacuum operating environment, high equipment costs, generally requires sample pretreatment, and cannot perform biological sample detection, thus limiting its applicatio...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a detection method for a single nanoparticle, which can perform label-free and fast imaging detection on a single nanoparticle, which solves the deficiency that the optical microscope cannot image nanomaterials in the prior art, and also compensates for the electronic The shortcomings of traditional nano-microscopic instruments such as microscopes, such as long detection time, high cost, and vacuum operation, also make up for the imaging problems caused by the fluorescence bleaching effect of total internal reflection fluorescence microscopy.

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