What is quenching in luminescence?
What is quenching in luminescence?
In luminescence spectroscopy, quenching refers to any process that leads to a reduction in the luminescence intensity of the luminophore. Static and dynamic quenching are the most common types of luminescence quenching and will be described in the following sections.
What wavelength does quinine fluoresce at?
450 nm
Purpose: Quinine is a strongly fluorescent compound in dilute acid solution with two excitation wavelengths (250 and 350 nm) and a fluorescence emission at 450 nm.
What is collisional quenching?
Collisional quenching occurs when the excited fluorophore experiences contact with an atom or molecule that can facilitate non-radiative transitions to the ground state. Excited-state molecule collides with quencher molecule and returns to ground state non-radiatively.
What is quenching with example?
quenching. 1. The process of extinguishing, removing, or diminishing a physical property such as heat or light; e.g., the cooling of a hot metal rapidly by plunging it into water or oil.
How does quinine fluorescence?
Quinine contains rare earth compounds called phosphors. These substances glow when they are hit with particular wavelengths of the EM spectrum, including UV light. Phosphors absorb UV light and then emit it in their own color.
What part of quinine is fluorescence?
Quinine is an alkaloid used to treat malaria. It is a strongly fluorescent compound in dilute solutions of H2SO4 (Φf=0.55). Quinine’s excitation spectrum has absorption bands at 250 nm and 350 nm and its emission spectrum has a single emission band at 450 nm….Example 10.6. 1.
| [quinine] (µg/mL) | If |
|---|---|
| 7.00 | 69.89 |
| 10.00 | 100.0 |
What is luminescence lifetime?
The luminescence lifetime is the time required for the energy of a population of excited fluorophores to decrease to 1/e of the maximum intensity via energy loss through luminescence (fluorescence or phosphorescence) and other nonradiative processes.
What is the process of quenching?
quenching, rapid cooling, as by immersion in oil or water, of a metal object from the high temperature at which it has been shaped. This usually is undertaken to maintain mechanical properties associated with a crystalline structure or phase distribution that would be lost upon slow cooling.
Why is quinine fluorescence?
What is dynamic quenching?
Per the recommendations of the International Union of Pure and Applied Chemistry (1), dynamic quenching is a process that interferes with emission from the excited state of a fluorophore after the excited state has formed.
Is tonic water luminescence?
A brief history of quinine, fluorescence and the probable origin of the G. Tonic water glows faintly in sunlight — a phenomenon that is even more apparent when it is illuminated by ultraviolet light. This glow, called fluorescence, is a special characteristic of tonic water’s main ingredient: quinine.
How do you determine quenching type?
Quenching occurs via two distinct pathways. Collisional quenching occurs when the excited state fluorophore is deactivated upon contact with some quencher molecule in solution. Static quenching occurs when a fluorophore forms a non-fluorescent complex with a quencher and is no longer excitable.
What is quenching of quinine?
The left sample contains chloride ions which quench quinine’s fluorescence, so the left sample does not fluoresce visibly (the violet light is just scattered laser light). Quenching refers to any process which decreases the fluorescence intensity of a given substance.
What is quenching in luminescence spectroscopy?
In luminescence spectroscopy, quenching refers to any process that leads to a reduction in the luminescence intensity of the luminophore. Static and dynamic quenching are the most common types of luminescence quenching and will be described in the following sections. A third type of quenching also exists, namely ‘inner-filter quenching’.
What color does quinine fluoresce?
Typically quinine fluoresces blue, visible in the right sample. The left sample contains chloride ions which quench quinine’s fluorescence, so the left sample does not fluoresce visibly (the violet light is just scattered laser light). Quenching refers to any process which decreases the fluorescence intensity of a given substance.
What are the types of quenching reactions?
A variety of processes can result in quenching, such as excited state reactions, energy transfer, complex-formation and collisional quenching. As a consequence, quenching is often heavily dependent on pressure and temperature. Molecular oxygen, iodide ions and acrylamide are common chemical quenchers.