A detection method of spr detection system based on external field modulation

Abstract

The invention provides a detection method of an SPR detection system based on external field modulation. The method includes the steps: 1) acquiring SPR angle scanning curves of a first sample solution and a second sample solution, calculating the sensitivity of the SPR detection system under a zero external field, and calibrating a detection dynamic range; 2) selecting a certain angle in the dynamic range as an incident angle, and carrying out external field scanning, to obtain the linear coefficient of change of the reflected light intensity along with the external field intensity; 3) introducing a to-be-measured solution, selecting an incident angle the same as that of the step 2), adjusting the applied external field intensity, allowing the detected reflected light intensity maintained in the dynamic range all the time, and reading out the external field intensity and the reflected light intensity; and 4) converting the measured reflected light intensity into an equivalent reflected light intensity under the zero external field based on the obtained linear coefficient, and then based on the sensitivity of the SPR detection system, calculating the refractive index or concentration of the to-be-measured solution by utilizing the equivalent reflected light intensity. The method can significantly expand the dynamic range of an adjustable surface plasma resonance sensor.

Description

technical field [0001] The invention relates to the field of sensors and sensing technology, in particular, the invention relates to a detection method based on a tunable surface plasmon resonance sensor. Background technique [0002] Surface plasmon resonance sensors are an optical sensing technology that can detect changes in the refractive index in regions near metal interfaces. Since the 1980s, SPR biosensors have been rapidly developed and widely used due to their outstanding label-free, fast and sensitive and real-time detection advantages. At present, it has been applied in the fields of protein interaction, nucleic acid interaction, food safety, pesticide residues, environmental safety, drug screening, rapid and sensitive detection of infectious diseases, etc. [0003] The tunable SPR biosensor is based on the surface plasmon resonance excited by the combination of prism and waveguide. For the specific principle, please refer to the literature "J.Homola, Surface pla...

AI Technical Summary

Problems solved by technology

This solution needs to change the optical path through the mechanical structure, which often affects the accuracy and consistency of the experiment, and also needs to interrupt the experiment, and rescan and calibrate the SPR curve

[0005] Therefore, the small dynamic range seriously affects the practicability of tunable SPR, a new type of SPR sensor, and there is an urgent need for a detection scheme based on a tunable SPR biosensor with a large dynamic range.

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