Method for obtaining fluorescence emission spectrum information of single polymer molecule in shearing field

Abstract

The invention discloses a method for obtaining fluorescence emission spectrum information of a single polymer molecule in a shearing field. The method comprises the following steps: (1) preparation of a polymer solution whose concentration is less than 10nM, and a fluorescence molecule probe is labelled on the polymer molecule; (2) the shearing field is applied, the labelled polymer solution is irradiated by laser, an emitted fluorescence signal is collected and analyzed, and fluorescence emission spectrum information of the single polymer molecule is obtained; and a measuring system comprises an excitation light source unit, a shearing application and rheological measurement unit, an optical microscopy unit, and a single molecule fluorescence emission spectrum measurement unit, wherein, the bottom part of the shearing application and rheological measurement unit is provided with an excitation light optical window. Macroscopic shearing application, rheological measurement and single molecule fluorescence emission spectrum measurement are combined, and the single molecule fluorescence emission spectrum of the system to be measured in the shearing field is obtained, wherein detection space is at 10<-15>L level, and sensitivity of single molecule level is provided.

Description

Technical field [0001] The invention relates to a method for obtaining fluorescence emission spectrum information of a single polymer molecule under a shear field, and belongs to the field of basic research on polymer physics. Background technique [0002] The conformational information of polymer molecules, especially charged polymers, in their good solvents is a problem that academic circles pay attention to but are rarely understood. This problem is inseparable from the microscopic environment near the polymer chain, such as the distribution of counter ions. Measuring single-molecule fluorescence emission spectra is an effective way to solve this problem. This will help us better understand the microscopic physical processes of the macroscopic properties of polymer solutions, and will also help us uncover the microscopic physical nature of some life processes. [0003] The spectrum can be roughly divided into absorption spectrum and emission spectrum. Infrared absorption spectr...

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Problems solved by technology

[0004] However, due to concentration limitations, ultraviolet absorption spectroscopy and infrared absorption spectroscopy cannot study the microscopic physical information of polymer solutions from the perspective of single molecules. Although fluorescence correlation spectroscopy has the resolution and sensitivity of single molecules, it cannot obtain the distribution of light intensity. information, it is impossible to intuitively obtain the changes in the microscopic physical environment around the chain

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