Spectrofluorometer
Instrument for measuring chemical composition
title: "Spectrofluorometer" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["laboratory-equipment", "spectrometers"] description: "Instrument for measuring chemical composition" topic_path: "general/laboratory-equipment" source: "https://en.wikipedia.org/wiki/Spectrofluorometer" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Instrument for measuring chemical composition ::
::figure[src="https://upload.wikimedia.org/wikipedia/commons/0/0f/Schematic-diagram-of-the-arrangement-of-optical-components-in-a-typical_Spectrofluorometer.png" caption="url=https://www.labcompare.com/10-Featured-Articles/171083-Spectrofluorometers-Tools-for-Measuring-Fluorescence-Signature/}} The instrument is used in [[fluorescence spectroscopy]]."] ::
Operation
Generally, spectrofluorometers use high intensity light sources to bombard a sample with as many photons as possible. This allows for the maximum number of molecules to be in an excited state at any one point in time. The light is either passed through a filter, selecting a fixed wavelength, or a monochromator, which allows a wavelength of interest to be selected for use as the exciting light. The emission is collected at the perpendicular to the emitted light. The emission is also either passed through a filter or a monochromator before being detected by a photomultiplier tube, photodiode, or charge-coupled device detector. The signal can either be processed as digital or analog output.
Systems vary greatly and a number of considerations affect the choice. The first is the signal-to-noise ratio. There are many ways to look at the signal to noise of a given system but the accepted standard is by using the Raman signal of water. Sensitivity or detection limit is another specification to be considered, that is how little light can be measured. The standard would be fluorescein in NaOH, typical values for a high end instrument are in the femtomolar range.
Auxiliary components
These systems come with many options, including:
- Polarizers
- Peltier temperature controllers
- Cryostats
- Cold Finger Dewars
- Pulsed lasers for lifetime measurements
- LEDs for lifetimes
- Filter holders
- Adjustable optics (very important)
- Solid sample holders
- Slide holders
- Integrating spheres
- Near-infrared detectors
- Bilateral slits
- Manual slits
- Computer controlled slits
- Fast switching monochromators
- Filter wheels
References
References
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::