The key difference between steady state and time resolved fluorescence is that the steady-state fluorescence involves the study of long-term average fluorescence of a sample when irradiated with UV, visible or near IR light, whereas the time-resolved fluorescence involves the study of fluorescence of a sample that is monitored as a function of time after the excitation by a light pulse.
Fluorescence can be defined as the visible or invisible radiation that emits from a substance due to the incident radiation of a short wavelength. In other words, it is the emission of light by a substance having absorbed light or other types of EMR (electromagnetic radiation). The most common example for fluorescence is the absorption of radiation in the UV region of the spectrum by a sample (which is invisible to us) and emitting the light in the visible region. This gives the sample a distinct color that is observable only upon UV light. Moreover, fluorescent materials tend to glow nearly immediately upon the removal of the radiation source.
CONTENTS
1. Overview and Key Difference
2. What is Steady-State Fluorescence
3. What is Time-Resolved Fluorescence
4. Steady State vs Time-Resolved Fluorescence in Tabular Form
5. Summary
What is Steady-State Fluorescence?
A steady-state fluorescence is an analytical technique that studies the long-term average fluorescence of a sample upon the irradiation of that sample with UV, visible, or near IR light. The applications of steady-state fluorescence include excitation and emission scans, synchronous scans and maps, steady-state fluorescence anisotropy, excitation-emission maps, kinetic measurements, and temperature maps.
What is Time-Resolved Fluorescence?
A time-resolved fluorescence is an analytical technique that studies the fluorescence of a sample that is monitored as a function of time after the excitation by a light pulse. We can name it an extension of fluorescence spectroscopy. In this technique, we need to monitor a sample (after its excitation through a flash of light) as a function of time.
There are different ways that we can obtain a time-resolved fluorescence, including fast-detection electronics, time-correlated single-photon counting, a streak camera, intensified CCD cameras, optical gating, etc. During the time-resolved fluorescence, the convolution integral is used to calculate a lifetime from fluorescence decay.
What is the Difference Between Steady State and Time Resolved Fluorescence?
Fluorescence can be defined as the visible or invisible radiation that emits from a substance due to the incident radiation of a short wavelength. There are two derivatives of fluorescence as steady-state and time-resolved fluorescence. The key difference between steady state and time resolved fluorescence is that the steady-state fluorescence involves the study of long-term average fluorescence of a sample when irradiated with UV, visible or near IR light, whereas the time-resolved fluorescence involves the study of fluorescence of a sample that is monitored as a function of time after the excitation by a light pulse.
A steady-state fluorescence is used in excitation and emission scans, synchronous scans and maps, steady-state fluorescence anisotropy, excitation-emission maps, kinetic measurements, and temperature maps. A time-resolved fluorescence, on the other hand, is used in TR-FRET systems (time-resolved fluorescence energy transfer)
The following table summarizes the difference between steady state and time resolved fluorescence.
Summary – Steady State vs Time Resolved Fluorescence
The steady-state fluorescence and time-resolved fluorescence are very important approaches in analytical and physical chemistry. The key difference between steady-state and time-resolved fluorescence is that the steady-state fluorescence involves the study of long-term average fluorescence of a sample when irradiated with UV, visible or near IR light, whereas the time-resolved fluorescence involves the study of fluorescence of a sample that is monitored as a function of time after the excitation by a light pulse.
Reference:
1.“Steady State Fluorescence: Fluorescence Spectroscopy Technique.” Edinburgh Instruments, 28 Apr. 2020.
Image Courtesy:
1. “EuAPC exem overlay annotated.” By Josh-eaton – Own work (CC BY-SA 3.0) via Commons Wikimedia