Introduction to the composition structure of fluorescence spectrophotometer

A fluorescence spectrophotometer is an instrument
used to scan the fluorescence spectrum emitted by a liquid phase fluorescent marker.

It can provide many physical parameters including excitation spectroscopy, emission spectra, fluorescence intensity, quantum yield, fluorescence lifetime, fluorescence polarization, etc.
, reflecting the bonding and structure of molecules from various angles
.

Through the determination of these parameters, not only can general quantitative analysis be done, but also the conformational changes of molecules in various environments can be inferred, so as to elucidate the relationship between
molecular structure and function.

The excitation wavelength scanning range of the fluorescence spectrophotometer is generally 190~650nm, and the emission wavelength scanning range is 200~800nm
.

Can be used for spectral scanning of liquid, solid samples such as gel strips
.

Composition 1.
Light source: high-pressure mercury vapor lamp or xenon arc lamp, the latter can emit a continuous spectrum of greater intensity, and the intensity is almost equal in the range of 300nm to 400nm, so it is more commonly used
.

2.
Excitation monochromator: placed between the light source and the sample chamber is an excitation monochromator or a monochromator to screen out a specific excitation spectrum
.

3.
Emission monochromator: placed between the sample chamber and the detector is an emission monochromator or a di-monochromator, and the grating is often used as a monochromator
.

Filter out specific emission spectra
.

4.
Sample chamber: usually composed of a quartz cell (for liquid samples) or a solid sample holder (powder or sheet sample).


When measuring liquids, the light source is arranged at right angles with the detector; When measuring solids, the light source is arranged
at an acute angle with the detector.

5.
Detector: Photoelectric tube or photomultiplier tube is generally used as detector
.

The optical signal can be amplified and converted into an electrical signal
.