This document provides an overview of fluorescence spectroscopy. It describes how luminescence occurs when a system absorbs external energy like light and emits photons. Specifically, fluorescence involves absorbing ultraviolet or visible light which causes molecule excitation, then reemission of light. The document outlines fluorescence instrumentation components like light sources, wavelength selection using filters or monochromators, detectors, and sample holders. It also discusses related topics such as phosphorescence, absorption spectra, and the advantages and disadvantages of fluorescence spectroscopy.
describes the complete history, mechanisms, instrumentation(jablonski diagram), types, comparision and factors affecting, applications of fluorescence and phosphorescence and describes about quenching and stokes shift.
Fluorescence , Phosphorescence and photoluminescencePreeti Choudhary
luminescence, fluorescence and example of fluorescence, phosphorescence , Jablonski diagram, Photoluminescence.
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This presentation is about the monochromators and specifically their use in spectroscopy. It includes definition, principle, origin of term, principle, types, prism monochromator, diffraction grating monochromator, difference in both of them, their uses and working as well, optical filters and their uses and application.
A Monochromator is an optical device that transmits a mechanically selectable narrow band of wavelengths of light chosen from a wider range of wavelengths available at the input. And the unwanted radiations are blocked by the slit allowing only the desired ray to pass (monochromatic).
A dispersive element disperse the polychromatic light into several bands of single wavelength and then a slit is used which stops the unwanted bands of light, allowing only the desired monochromatic light to pass through its exit point.
By fixing the slit and rotating the dispersive element, the direction of the dispersed light is turned so that the colour of the resulting monochromatic light changes.
When electromagnetic radiation passes through a prism, it is refracted because the index of refraction of the prism material is different from that of air.
Shorter wavelengths are refracted more than longer wavelengths.
By rotation of the prism, different wavelengths of the spectrum can be made to pass through an exit slit and through the sample.
A prism works satisfactorily in the ultraviolet and visible regions and can also be used in the infrared region.
Because of its nonlinear dispersion, it works more effectively for the shorter wavelengths.
Glass prisms and lenses can be used in the visible region.
Quartz or fused silica must be used in the ultraviolet region.
The entire monochromatic compartment must be kept dry.
It would be use full to All Needy People. It involve information about NMR Spectroscopy ( a spectroscopic techniques), factors influencing , proton NMR and their applications of NMR as well as Nuclear magnetic imaging.
Fluorescence spectroscopy becomes a widely used tool at the interface of biology, chemistry and physics, because of its precise sensitivity and recent technical advancements. The measurements can provide information on a wide range of molecular processes including the interactions of solvent molecules with fluorophores, rotational diffraction of biomolecules, distance between sites of biomolecules, conformational changes and binding interactions. These advances in fluorescence technology are decreasing the cost and complexity of previously complex processes. Fluorescence spectroscopy is a highly developed and non-invasive technique that enables the on-line measurements of substrate and product concentrations or the identification of characteristic process states.
Fluorescence spectroscopy is a very advanced technology that uses the phenomena of fluorescence. This presentation covers the basic concepts, instrumentation, applications, advantages and disadvantages of the technique. It also covers the Jablonski diagram. The process that analyses and measure these types of emissions is known as Fluorescence spectroscopy.Fluorescence spectroscopy is a novel technique that is used for measuring the binding of ligands to the proteins in the presence of fluorphore that bound to the ligand .
describes the complete history, mechanisms, instrumentation(jablonski diagram), types, comparision and factors affecting, applications of fluorescence and phosphorescence and describes about quenching and stokes shift.
Fluorescence , Phosphorescence and photoluminescencePreeti Choudhary
luminescence, fluorescence and example of fluorescence, phosphorescence , Jablonski diagram, Photoluminescence.
https://www.linkedin.com/in/preeti-choudhary-266414182/
https://www.instagram.com/chaudharypreeti1997/
https://www.facebook.com/profile.php?id=100013419194533
https://twitter.com/preetic27018281
Please like, share, comment and follow.
stay connected
If any query then contact:
chaudharypreeti1997@gmail.com
Thanking-You
Preeti Choudhary
The all the content in this profile is completed by the teachers, students as well as other health care peoples.
thank you, all the respected peoples, for giving the information to complete this presentation.
this information is free to use by anyone.
This presentation is about the monochromators and specifically their use in spectroscopy. It includes definition, principle, origin of term, principle, types, prism monochromator, diffraction grating monochromator, difference in both of them, their uses and working as well, optical filters and their uses and application.
A Monochromator is an optical device that transmits a mechanically selectable narrow band of wavelengths of light chosen from a wider range of wavelengths available at the input. And the unwanted radiations are blocked by the slit allowing only the desired ray to pass (monochromatic).
A dispersive element disperse the polychromatic light into several bands of single wavelength and then a slit is used which stops the unwanted bands of light, allowing only the desired monochromatic light to pass through its exit point.
By fixing the slit and rotating the dispersive element, the direction of the dispersed light is turned so that the colour of the resulting monochromatic light changes.
When electromagnetic radiation passes through a prism, it is refracted because the index of refraction of the prism material is different from that of air.
Shorter wavelengths are refracted more than longer wavelengths.
By rotation of the prism, different wavelengths of the spectrum can be made to pass through an exit slit and through the sample.
A prism works satisfactorily in the ultraviolet and visible regions and can also be used in the infrared region.
Because of its nonlinear dispersion, it works more effectively for the shorter wavelengths.
Glass prisms and lenses can be used in the visible region.
Quartz or fused silica must be used in the ultraviolet region.
The entire monochromatic compartment must be kept dry.
It would be use full to All Needy People. It involve information about NMR Spectroscopy ( a spectroscopic techniques), factors influencing , proton NMR and their applications of NMR as well as Nuclear magnetic imaging.
Fluorescence spectroscopy becomes a widely used tool at the interface of biology, chemistry and physics, because of its precise sensitivity and recent technical advancements. The measurements can provide information on a wide range of molecular processes including the interactions of solvent molecules with fluorophores, rotational diffraction of biomolecules, distance between sites of biomolecules, conformational changes and binding interactions. These advances in fluorescence technology are decreasing the cost and complexity of previously complex processes. Fluorescence spectroscopy is a highly developed and non-invasive technique that enables the on-line measurements of substrate and product concentrations or the identification of characteristic process states.
Fluorescence spectroscopy is a very advanced technology that uses the phenomena of fluorescence. This presentation covers the basic concepts, instrumentation, applications, advantages and disadvantages of the technique. It also covers the Jablonski diagram. The process that analyses and measure these types of emissions is known as Fluorescence spectroscopy.Fluorescence spectroscopy is a novel technique that is used for measuring the binding of ligands to the proteins in the presence of fluorphore that bound to the ligand .
a substance can absorb any visible light or external radiation and then again emit it. this called fluorescence and the process of reduction in fluorescence intensity is called quenching. this presentation is all about quenching of fluorescence.
Photoluminescence Spectroscopy for studying Electron-Hole pair recombination ...RunjhunDutta
Description of Photoluminescence Spectroscopy: Principle, Instrumentation & Application.
Three research papers have been summarized which lay stress on Photoluminescence Study for Electron-Hole Pair Recombination for characterizing the properties of semiconductors used in Photoelectrochemical Splitting of Water.
http://www.redicals.com
The spectrophotometer technique is to measures light intensity as a function of wavelength.
• Measures the light that passes through a liquid sample
• Spectrophotometer gives readings in Percent Transmittance (%T) and in Absorbance (A)
Seminar on Uv Visible spectroscopy by Amogh G VAmoghGV
PPT of seminar on UV Visible spectroscopy, electronic transitions, Instrumentation of Double beam spectrophotometers, Advantages of Double beam over single beam, Beer Lamberts law derivation
Infrared Spectroscopy and UV-Visible spectroscopyPreeti Choudhary
Instrumentation of Infrared Spectroscopy and UV-Vis spectroscopy
Discuss the fundamentals and concepts behind Infrared and UV-Vis spectroscopy.
I hope this presentation helpful for you.
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A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
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In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
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This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
2. LUMINISCENCE AND THE NATURE OF
LIGHT
A hot body that emits radiation solely because of its
high temperature is said to exhibit incandescence.
All other forms of light emission are called
luminescence.
When luminescence occurs, the system loses
energy and if the emission is to be continuous,
some form of energy must be supplied from
elsewhere.
When the external energy supply is by means of
the absorption of infrared, visible or ultraviolet light,
the emitted light is called photoluminescence and
this is the process that takes place in any
fluorimetric analysis.
3. The energy, E, carried by any one quantum is
proportional to its frequency of oscillation, that is
E = hν = hc/ λ ergs
Since the amount of energy per einstein is
proportional to the frequency of the radiation, it
varies enormously over the range of the electromagnetic spectrum, as shown in the following table.
4.
5. The absorption of light results in the formation of
excited molecules which can in turn dissipate their
energy by decomposition, reaction, or re-emission.
The efficiency with which these processes take
place is called the quantum efficiency and in the
case of photoluminescence can be defined as:
ФE = einsteins emitted or no. of quanta emitted/
einsteins absorbed or no. of quanta absorbed and
never exceeds unity.
6. FLUORESCENCE
At room temperature most molecules occupy the lowest
vibrational level of the ground electronic state, and on
absorption of light they are elevated to produce excited states.
7. A plot of emission against wavelength for any given excitation wavelength is
known as the emission spectrum. If the wavelength of the exciting light is
changed and the emission from the sample plotted against the wavelength of
exciting light, the result is known as the excitation spectrum. Furthermore, if
the intensity of exciting light is kept constant as its wavelength is changed, the
plot of emission against exciting wavelength is known as the corrected
excitation spectrum. The quantum efficiency of most complex molecules is
independent of the wavelength of exciting light and the emission will be
directly related to the molecular extinction coefficient of the compound; in
other words, the corrected excitation spectrum of a substance will be the
same as its absorption spectrum.
8. PHOSPHORESCENCE
The indirect process of conversion from the excited
state produced by absorption of energy, the singlet
state, to a triplet state, is known as intersystem crossing.
Direct transition from the ground state, usually a singlet
state, for a molecule with an even number of electrons,
to an excited triplet state is theoretically forbidden, which
means that the reverse transition from triplet to ground
state will be difficult.
Thus, while the transition from an excited singlet state,
for example, S1, to the ground state with the emission of
fluorescence can take place easily and within 10-9 - 106 seconds, the transition from an excited triplet state to
the ground state with the emission of phosphorescence
requires at least 10-4 seconds and may take as long as
102 seconds.
9.
10.
The triplet state of a molecule has a lower energy than its
associated singlet state so that transitions back to the ground
state are accompanied with the emission of light of lower
energy than from the singlet state. Therefore, we would
typically expect phosphorescence to occur at longer
wavelengths than fluorescence.
11. LIGHT SCATTERING
Rayleigh-Tyndall scattering
Incident radiation is not only absorbed or transmitted by
the sample but is also scattered in all directions. The
scattering takes place either from the molecules
themselves (Rayleigh scattering) or from small particles
in colloidal suspension (Tyndall scattering).
Raman scattering
During the Rayleigh scattering process, some of the
incident energy can be abstracted and converted into
vibrational and rotational energy. The resulting energy
scattered is therefore of lower energy and longer
wavelength than the incident radiation.
12. BEER LAMBERT LAW
Io/I = e –Ecl
Normally written as:
log10 Io/I = Ecl
Absorption spectra are simply a plot of absorbance
against wavelength for any sample.
13. INSTRUMENTATION
All fluorescence instruments contain three basic items: a
source of light, a sample holder and a detector.
Simple and sophisticated filter fluorimeters. Simple
fluorescence spectrometers have a means of analysing the
spectral distribution of the light emitted from the sample, the
fluorescence emission spectrum, which may be by means of
either a continuously variable interference filter or a
monochromator. In more sophisticated instruments,
monochromators are provided for both the selection of
exciting light and the analysis of sample emission.
14.
15. LIGHT SOURCES
Commonly employed sources in fluorescence
spectrometry have spectral outputs either as a
continuum of energy over a wide range or as a
series of discrete lines. An example of the first type
is the tungsten-halogen lamp and of the latter, a
mercury lamp.
It is advantageous to employ a source whose
output is a continuum and the most commonly
employed type is the xenon arc.
16. WAVELENGTH SELECTION
The simplest filter fluorimeters use fixed filters to isolate both
the excited and emitted wavelengths. To isolate one particular
wavelength from a source emitting a line spectrum, a pair of
cut-off filters are all that is required. These may be either glass
filters or solutions in cuvettes.
Recently, interference filters having high transmission (≈ 40%)
of a narrow range (10 – 15 nm) of wavelengths have become
available and it is possible to purchase filters with a maximum
transmission at any desired wavelength. UV filters of this type,
however, are expensive and of limited range.
However, it is useful to be able to scan the emission from the
sample to check for impurities and optimize conditions. A
convenient method is to make use of a continuous
interference filter so that an emission spectrum can be
recorded, at least over the visible region of the spectrum.
17. A further refinement would be to use
monochromators to select both the excitation and
emission wavelengths.
Such a fluorescence spectrometer is capable of
recording both excitation and emission spectra and
therefore makes full use of the analytical potential
of the technique
If monochromators are employed, it should be
possible to change the slit width of both the
excitation and emission monochromators
independently.
18. DETECTORS
All commercial fluorescence instruments use
photomultiplier tubes as detectors and a wide
variety of types are available. The material from
which the photocathode is made determines the
spectral range of the photomultiplier and generally
two tubes are required to cover the complete UVvisible range. The S5 type can be used to detect
fluorescence out to approximately 650 nm, but if it
is necessary to measure emission at longer
wavelengths, a special red sensitive, S20,
photomultiplier should be employed.
19. READ OUT DEVICES
The output from the detector is amplified and
displayed on a readout device which may be a
meter or digital display.
Microprocessor electronics provide outputs directly
compatible with printer systems and computers,
eliminating any possibility of operator error in
transferring data.
20. SAMPLE HOLDERS
The majority of fluorescence assays are carried out in
solution, the final measurement being made upon the
sample contained in a cuvette or in a flowcell.
Cuvettes may be circular, square or rectangular (the
latter being uncommon), and must be constructed of a
material that will transmit both the incident and emitted
light.
Square cuvettes, or cells will be found to be most
precise since the parameters of pathlength and
parallelism are easier to maintain during manufacture.
However, round cuvettes are suitable for many more
routine applications and have the advantage of being
less expensive.
The cuvette is placed normal to the incident beam. The
resulting fluorescence is given off equally in all
directions, and may be collected from either the front
surface of the cell, at right angles to the incident beam,
or in-line with the incident beam.
21. Advantages
of fluorescence spectroscopy:
Very sensitive
Can be used for quantitation of fluorescent species
Easy and quick to perform analysis
Disadvantages:
Not useful for identification
Not all compounds fluorescence
Contamination can quench the fluorescence and
hence give false/no results