Fluorescence Spectroscopy

Some molecules fluoresce, that is, when they receive light of a specific wavelength, they will emit light in response. This emitted light carries information on the molecules’ structure and environment. The analysis of emitted light using spectroscopic techniques is a powerful analytical technique. Fluorescent spectroscopy can for example be used to identify organic compounds or check liquid samples for pollutants. In some cases, it is an alternative to standard analytical chemical techniques, like HPLC analysis. A range of fluorometers is available for different applications.

Fluorolog-QM | Modular Research Fluorometer for Lifetime and Steady State Measurements

Duetta | Fluorescence and Absorbance Spectrometer

Aqualog-Water Treatment Plant Analyzer | Automated Organic Analysis & Early Warning Sentinel

Aqualog Environmental Water Research Analyzer | The Gold Standard for Water

Aqualog-A TEEM Industrial QC/QA Analyzer | A Simple, Fast, “Column Free” Molecular Fingerprinting Technology

FluoroMax | Steady State and Lifetime Benchtop Spectrofluorometer



DeltaFlex | TCSPC Lifetime Fluorometer

DeltaPro | TCSPC Lifetime Fluorometer

Nanolog | Steady State and Lifetime Nanotechnology EEM Spectrofluorometer



DeltaTime | TCSPC Lifetime Kit

FLIMera | Imaging camera for dynamic FLIM studies at real time video rates


Ultima | Ultra Fast TCSPC Lifetime Fluorometer


Custom Spectroscopy Solutions

Modular Raman | Modular Raman Solutions
Photoluminescence | Flexible Photoluminescence (PL) Systems
Standard Microscope Spectroscopy Solutions (SMS) | Spectrocopy Solutions based on standard microscopes
Time Resolved Fluorescence | Modular Time Resolved Systems

How does Fluorescence Spectroscopy work?

Many organic molecules show fluorescence, especially those with fused ring structures or certain conjugated double bond structures. A number of metallic compounds also show fluorescence. In fluorescent molecules, incident light excites electrons. These excited states will quickly release part of the excess energy in the form of photons.
The basic scheme of fluorescence spectroscopes is straightforward: light from a light source passes through a diffraction grating monochromator and then reaches the sample. Here, part of the light will be absorbed and elicit fluorescence in some molecules. Part of the emitted light will reach a detector, via another diffraction grating monochromator. To minimize the risk of incident light falling directly onto the detector, light source and detector are placed at a 90 degree angle.

The light which is thus emitted and detected can be analyzed using spectroscopic techniques. Intensity and peak wavelength are affected by different variants in the environment of the molecule, such as the concentration of the fluorescent molecule, interactions with other molecules, or the temperature of the sample. The analysis of emitted light can provide both qualitative and quantitative information. Apart from the fluorescence, it is also possible to measure the absorbance spectrum of a compound.

Why use Fluorescence Spectroscopy?

This technique is well suited for measuring compounds in solution. It is easy to perform and versatile: measurement can be made over a wide time range, for example to measure the decay in fluorescence. Furthermore, the technique is very sensitive, with detection levels as low as one part in 1010.

ST Instruments provides a wide range of Fluorescence instrumentation from Horiba Scientific. An interesting application is Excitation Emission Matrix (EEM), a 3D scan that results in a plot of excitation wavelength versus emission wavelength versus fluorescence intensity, which can provide a molecular fingerprint. The A-TEEM™ from Horiba Scientific can simultaneously acquire Absorbance, Transmittance and fluorescence Excitation Emission Matrix measurements.

Applications of Fluorescence Spectroscopy

Discover the power of Fluorescence. From life sciences to materials, including water and forensics, Fluorescence is found in many fields of applications.