Fluorescence Quenching
Fluorescence Quenching - Related Videos
10:57
Quenching and Boiling
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2023
Source: Alexander S Rattner, Sanjay Adhikari, and Mahdi Nabil; Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA Controlled heating followed by rapid cooling is an important element of many materials processing applications. This heat-treating procedure can increase material hardness, which is important for cutting tools or surfaces in high wear environments. The rapid cooling stage is called quenching, and is often performed by immersing...
10:55
Fluorescence-quenching of a Liposomal-encapsulated Near-infrared Fluorophore as a Tool for In Vivo Optical Imaging
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Cited by 15 •
2015
The use of fluorophores for in vivo imaging can be greatly limited by opsonization, rapid clearance, low detection sensitivity and cytotoxic effects on the host. Encapsulation of fluorophores in liposomes by film hydration and extrusion leads to fluorescence quenching and protection which enables in vivo imaging with high detection sensitivity.
07:47
Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases
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Cited by 7 •
2016
Quorum-quenching enzymes are anti-virulent and anti-bacterial options that can mitigate pathogenesis without risk of incurring resistance, by preventing the expression of virulence factors and genes associated with antibiotic resistance and biofilm formation. In this study, we report a method that demonstrates the efficacy of quorum-quenching enzymes in bacterial biofilm disruption.
08:58
Cerebral Blood Oxygenation Measurement Based on Oxygen-dependent Quenching of Phosphorescence
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Cited by 28 •
2011
We present an experimental procedure for measuring the partial pressure of oxygen (pO2) in cerebral vasculature based on oxygen-dependent quenching of phosphorescence. Animal preparation and imaging procedures were outlined for both large field of view CCD-based imaging of pO2 in rats and 2-photon excitation based imaging of pO2 in mice.
08:07
Sample Preparation for Single Cell Mass Spectrometry Metabolomics Studies: Combined Cell Washing, Quenching, Drying, and Storage
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Cited by 1 •
2025
This protocol aims to preserve cell metabolites for single-cell mass spectrometry (SCMS) by combining volatile salt solution washing, rapid liquid nitrogen quenching, freeze-drying, and −8 °C storage. It demonstrates that liquid nitrogen quenching is essential for maintaining metabolite profiles, while prolonged cold storage should be minimized to prevent metabolic alterations.
FAQs
Dynamic quenching occurs when collisions with a quencher deactivate an excited fluorophore, whereas static quenching results from forming a nonfluorescent complex in the ground state. This distinction matters because both processes reduce fluorescence intensity but reflect different molecular interactions. Identifying the relevant mechanism helps chemists interpret signal changes in terms of molecular association or excited-state encounters.
Electron transfer and energy transfer provide alternative routes for removing excitation energy without producing the observed fluorescence. In electron transfer, the excited molecule participates in a charge-transfer process; in energy transfer, excitation is passed through an interaction involving another species. These pathways connect fluorescence loss to chemical environment and can help characterize molecular interactions or photochemical behavior.
Oxygen can act as a source of fluorescence quenching by providing a pathway for excited-state deactivation. Its presence therefore links the measured signal to environmental conditions as well as to the fluorophore itself. Monitoring changes associated with oxygen can support chemical sensing and help researchers evaluate how surrounding conditions influence excited-molecule behavior.
Researchers can measure fluorescence intensity while varying the quencher concentration, then use the Stern-Volmer relationship to connect the observed signal reduction with the amount of quencher present. This quantitative treatment turns fluorescence loss into concentration-related information. It is useful for characterizing interactions, comparing reaction conditions, and evaluating whether a chemical system responds systematically to its environment.
A supported workflow begins by observing the fluorophore’s fluorescence, introducing or varying a potential quencher, and recording the resulting intensity changes. Researchers then compare the measurements across conditions and apply a quantitative relationship such as the Stern-Volmer model when appropriate. The resulting pattern can reveal interaction behavior and provide information about reaction or environmental conditions.
The technique is useful when a target or surrounding condition changes the fluorescence signal through molecular interaction or excited-state deactivation. Because intensity changes can be measured and related to quencher concentration, the approach supports chemical sensing and bioanalytical assays. It can provide a practical signal for tracking analytes, interactions, or environmental factors within a chemical system.
Fluorescence quenching provides evidence that an excited fluorophore is losing energy through a particular interaction or deactivation pathway. In photochemistry, this helps connect fluorescence behavior with electron transfer, energy transfer, or other chemical processes. During reaction-mechanism studies, changes in intensity under different conditions can help characterize molecular interactions and clarify how the reaction environment affects excited states.