G6- Fluorescence Spectrophotometry

Question 1

• also known as “fluorimetry” or “spectrofluorometry”
• a method used to investigate the molecular and atomic interactions by examining the fluorescents emitted from a sample.

Answer 1

Fluorescence spectrophotometry

Question 2

Fluorescence spectrophotometry also known as fluorimetry or spectrofluorometry is a method used to investigate the ___ and ___ interactions by examining the fluorescents emitted from a sample

Answer 2

molecular and atomic interactions

Question 3

is a type of luminescence caused by photons exciting a molecule raising it to an electronic excited state

Answer 3

fluorescence

Question 4

is a method used to measure how much a chemical substance absorbs light by measuring the intensity of light as a beam of light passes through sample solution

Answer 4

spectrophotometry

Question 5

The process begins with the absorption of ___ by ____ which result in the promotion of an electron to a higher energy state.

Answer 5

photon ( light)
molecule ( fluorophore

Question 6

absorb energy excites the molecule from its ground state to an excited state. As the excited molecule returns to the ground state it emits a photon of ____ (corresponding to a longer wavelength) than the absorb photon

Answer 6

lower energy

Question 7

illustrates the transition of electronic states during fluorescence. It shows the energy levels in the absorbent spectrum of a typical fluorescent molecule

Answer 7

Joblonski diagram

Question 8

Joblonski diagram illustrates the transition of ____ states during fluorescence.

Answer 8

electronic

Question 9

•Refers to the average time/duration of fluorophore spends in the excited state before releasing a photon and returning to its ground state.
•It can vary from picoseconds to hundereds of nanoseconds depending on the fluorophore.

Answer 9

Fluorescence lifetime

Question 10

excited state formula

Answer 10

I(t) = Be^t/T (di jud siya T pero ana iyang na nawong)

Question 11

t
T
B
??

Answer 11

t- time

T- fluorescence lifetime

B- pre-exponential factor

Question 12

THE INSTRUMENT IS FITTED WITH A ___ __ THAT CAN EMIT RADIATION IN THE ULTRAVIOLET, VISIBLE, AND NEAR INFRARED WAVELENGTHS

Answer 12

LIGHT SOURCE

Question 13

SELECT A SPECIFIC WAVELENGTH OF LIGHT FROM THE BROAD SPECTRUM EMITTED BY THE LIGHT SOURCE

Answer 13

MONOCHROMATOR

Question 14

MONOCHROMATOR is composed of:

Answer 14

entrance slit
Collimating lens
Diffraction grating or prism
Exit slit

Question 15

controls the width of the incident light beam

Answer 15

Entrance slit

Question 16

converts divergent light rays into parallel rays

Answer 16

Collimating lens

Question 17

selects a narrow range of wavelengths for excitation

Answer 17

Diffraction grating or prism

Question 18

which determines the bandwidth of the selected excitation of wavelength

Answer 18

Exit slit

Question 19

It is where the sample to be analyzed is placed. It is usually quartz cuvettes or a microplate designed to hold the sample securely and allow the excitation light to pass through it

Answer 19

Sample holder

Question 20

Sample holder is usually ___, ____ or a __ designed to hold that the sample securely and allow the excitation light to pass through it

Answer 20

quartz
cuvettes
microplate

Question 21

• measures the intensity of the fluorescence emitted by the sample. •Typically a photo multiplier tube or pmt and photodiode array or pda detector

Answer 21

Detector

Question 22

records and displays the fluorescence spectra obtained from the sample

Answer 22

Data output system

Question 23

GENERAL COMPONENTS

Answer 23

Light source
Monochromator
Sample holder
Detector
Data output system

Question 24

Analytical steps

Answer 24

Excitation
Emission
DETECTION AND MEASUREMENT
SPECTRAL ANALYSIS
QUANTIFICATION

Question 25

the sample is exposed to light at a specific wavelength. This energy is absorbed by the sample’s molecules, causing electrons to move to higher energy levels

Answer 25

Excitation

Question 26

the excited electrons return to their ground state, they emit fluorescence at longer wavelengths

Answer 26

Emission

Question 27

the ___ captures the emitted fluorescence, and its intensity is ___.

Answer 27

Detector
measured

Question 28

What happens in detection and measurement

Answer 28

The emitted light passes through a monochromator
• The monochromator filters out unwanted background light.
• The filtered fluorescence reaches the detector.
• The detector converts the optical signal into an electrical signal.

Question 29

by scanning the excitation wavelength across a range and recording the corresponding emission intensity, fluorescence spectrum is created

Answer 29

SPECTRAL ANALYSIS

Question 30

the intensity of the fluorescence signal can be related to the concentration of the fluorescent compound

Answer 30

QUANTIFICATION

Question 31

In Jablonski diagram, the ___ line is the ground state (S0), and ___ lines represent excited states (S1, S2, etc.)

Answer 31

Lowest lines
Higher lines

Question 32

• After reaching an excited state, the molecule rapidly loses some energy through ___ ___, which involves non-radiative transitions to lower vibrational levels within the same electronic state
• shown by downward wavy lines in Jablonski diagram

Answer 32

vibrational relaxation

Question 33

In some cases, the molecule can transition from an excited singlet state (S1) to a triplet state (T1) through ___ ___ (depicted by a crossing arrow).

Answer 33

intersystem crossing

Question 34

refers to the range of wavelengths of light that are allowed to pass through the exit slit

Answer 34

Bandwidth