Oxygen Quenching
Oxygen Quenching - Related Videos
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.
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...
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.
10:38
Synthesis and Calibration of Phosphorescent Nanoprobes for Oxygen Imaging in Biological Systems
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Cited by 2 •
2010
We present principles of oxygen measurements by phosphorescence quenching and review design of porphyrin-based dendritic nanosensors for oxygen imaging in biological systems.
09:08
Detecting Reactive Oxygen Species
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2023
Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are many deleterious effects associated with unchecked ROS production, including structural damage to DNA and other biological molecules. However, ROS can also be mediators of physiological signaling. There is accumulating evidence that ROS play significant roles in everything from activation of transcription factors to the mediation of...
FAQs
Higher oxygen concentration generally produces a larger loss of luminescence because more oxygen is available to interact with excited molecules during collisions. Those interactions open a nonradiative deactivation pathway, reducing the population that returns to the ground state by emitting light. The resulting intensity or lifetime change provides the measurable response used in engineering sensors.
Temperature, diffusion, and the local quencher and probe environment all influence the observed response. Temperature changes the conditions under which interactions occur, while diffusion governs how readily oxygen reaches the luminescent molecules. The surrounding probe material also affects that access. Controlling or characterizing these variables helps engineers distinguish oxygen effects from changes caused by sensor conditions.
Both signal intensity and emission lifetime can reveal oxygen-dependent quenching, but they represent different measured features of the same response. A calibration model relates the observed change to oxygen concentration, and Stern-Volmer analysis is one approach identified for quantifying that relationship. Using a defined measurement and calibration model supports consistent interpretation of sensor output.
Dye-coated films and fiber probes provide the main sensing formats described for optical oxygen sensors. A film places the luminescent dye in a coating, while a fiber probe carries the sensing function in a probe configuration. In either case, oxygen-induced changes in luminescence are converted into an oxygen measurement.
Calibration begins by measuring the sensor response under characterized oxygen conditions, using either luminescence intensity or lifetime as the observable. Engineers then relate those readings to oxygen concentration with a calibrated model. Stern-Volmer analysis can provide this quantitative framework, helping assess how consistently the device reports oxygen.
The approach is useful wherever oxygen concentration must be monitored through an optical response, including process monitoring, packaging, and biomedical devices. Its engineering value comes from translating quenching-related changes in a dye-coated film or fiber probe into a measurable signal. The same principle can address either dissolved or gaseous oxygen, provided the probe environment and calibration are appropriate.