Phosphorescent Probe
Phosphorescent Probe - Related Videos
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.
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.
01:23
Photoluminescence: Fluorescence and Phosphorescence
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2024
Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds. A pair of electrons in a...
01:26
Variables Affecting Phosphorescence and Fluorescence
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2024
Fluorescence and phosphorescence are essential phenomena in fields like analytical chemistry, biological imaging, and materials science, where they detect molecular properties and visualize cellular structures. Understanding the variables that influence these luminescent behaviors is crucial for maximizing accuracy and efficiency in their applications. These variables can broadly be grouped into chemical structure, solvent properties, and external conditions, each playing a distinct role in...
01:25
Fluorescence and Phosphorescence: Instrumentation
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2024
Fluorometers and spectrofluorometers are two types of instruments used for measuring molecular fluorescence. These instruments differ in how they select excitation and emission wavelengths and the type of light sources they utilize. Fluorometers use absorption interference filters to choose excitation and emission wavelengths. The excitation source in a fluorometer is typically a low-pressure mercury vapor lamp that emits intense lines distributed throughout the ultraviolet and visible regions.
FAQs
The triplet state gives the probe a longer-lived excited condition than the initial excited state. That extended lifetime creates a measurable delay between excitation and emission, allowing researchers to distinguish the probe’s signal from events occurring immediately after excitation. This temporal separation supports time-resolved measurements and helps reveal biochemical changes that may be difficult to observe through direct observation alone.
These conditions can change either the emitted light intensity, the emission lifetime, or both. Oxygen concentration provides information about local cellular conditions, while molecular binding and environmental changes can modify the probe’s behavior near a target. Measuring these signal changes therefore converts otherwise difficult-to-observe biochemical conditions into quantitative optical readouts.
Intensity describes how much phosphorescent light the probe emits, whereas lifetime describes how long the emission persists after excitation. Both can respond to oxygen concentration, binding, or the surrounding environment, but they report different features of the signal. Considering either or both measurements helps researchers characterize biochemical conditions more fully than relying on light output alone.
A typical workflow begins by introducing the probe into the biochemical system, exciting it, and then observing its delayed emission. Researchers can record the emitted intensity, lifetime, or changes in these values under different conditions. Comparing the optical response with the sample’s biochemical state allows the probe to report interactions, conformational changes, oxygen levels, or molecular activity.
When a probe responds to binding or to a change in molecular shape, its phosphorescence can change in intensity or lifetime. Researchers monitor that optical response while examining the biochemical system, using the difference between conditions as evidence of a molecular event. This approach provides an indirect way to follow interactions and structural changes that are not easily observed directly.
In biochemistry, these probes can monitor molecular interactions, conformational changes, cellular oxygen levels, and enzyme or metabolite activity. Their delayed emission also supports sensitive time-resolved imaging and quantitative assays. As a result, the same general reporting principle can be applied to cellular measurements, interaction studies, and analyses of biochemical activity.