Extinguishing weak fluorescence detection system

Abstract

The invention discloses an extinction type weak fluorescence detection system, comprising: an excitation light path, a light-shielding housing, a fluorescence collecting lens arranged in the light-shielding housing, a main dichroic mirror, a secondary dichroic mirror, a band-pass filter Light sheet, converging lens, photoelectric conversion detector, conical surface deluster. The present invention uses multiple dichroic mirrors in series to deeply filter the background excitation light entering the detection optical path, which can greatly reduce the energy ratio of the background excitation light in the target fluorescence, and can solve the problem that the fluorescence signal is easily excited by the background when the fluorescence signal is weak. The problem of light flooding; by setting the conical surface extinction device, the leaked incident excitation light can be efficiently absorbed, and the internal absorption surface of the detection optical path can be increased by using the slope method, and the light energy per unit area can be dispersed and reduced, thereby reducing the internally excited light. Interfering with fluorescence, increasing the turn-back times of leakage light absorption through the channel makes the extinction absorption more thorough, and then eliminates the fluorescence interference signal excited by the inner surface of the detection optical path, making the detection result more accurate.

Description

technical field [0001] The invention relates to the technical field of optical equipment, in particular to an extinction type weak fluorescence detection system. Background technique [0002] Fluorescence resonance energy transfer is an emerging molecular fluorescence detection technology that uses dipole interaction to transfer the energy of the donor excited state to the adjacent acceptor molecule. It has broad application prospects in biological macromolecular interaction, immunoassay, nucleic acid detection, etc. . Since the target fluorescence to be detected is not directly excited and converted by the excitation light, but the secondary fluorescence generated by the energy resonance transfer between the donor fluorescence and the adjacent acceptor, the fluorescence resonance energy transfer method generates the fluorescence resonance energy transfer method when the excitation light intensity is the same. The effective fluorescence intensity is much lower than the trad...

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Problems solved by technology

[0003] Because interference filters (including dichroic mirrors) cannot filter out 100% of the light in the stop band band, about 1% of the stop band light will still pass through to the other side of the filter (including dichroic mirrors). Therefore, when using the traditional fluorescence detection optical path, a part of the background excitation light will be mixed in the effective fluorescence and irradiated on the photoelectric conversion detector to cause interference to the fluorescence detection. When the intensity of the effective fluorescence is weak to less than the background excitation light, it will be Submerged by the background excitation light, it cannot be detected; in addition, when the high-intensity incident excitation light is irradiated on the dichroic mirror for the first time, about 1% of the excitation light is not filtered by reflection and passes through the dichroic mirror On the other hand, compared with the effective fluorescence, these missed excitation light energies are still huge. When using the traditional fluorescence detection optical path, they are easy to be absorbed on the internal light absorption surface of the detection optical path system and the surface of the filter (depending on the adhesive material of the filter film layer). ) to excite interference fluorescence signals, when the wavelength of internal interference fluorescence overlaps with the wavelength of effective fluorescence, it will affect the accuracy of subsequent detection

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