UV-Vis or Fluorescence Spectrophotometry

Question 1

basic principles of fluorescence spectrophotometry

Answer 1

1. fluorescence
2. spectrophotometry
3. fluorescence spectrophotometry
4. excitation
5. emission
6. fluorophore
7. Jablonski diagram
8. fluorescence lifetime (FLT)

Question 2

• form of luminescence
• substance’s emission of visible light after absorbing any form of electromagnetic radiation

Answer 2

fluorescence

Question 3

measure how much a chemical substance absorbs light by measuring the light’s intensity as a beam of light passes through a sample solution

Answer 3

spectrophotometry

Question 4

set of techniques that deal with the measurement of fluorescence that substances have emitted when they are exposed to UV, visible, or any electromagnetic radiation

Answer 4

fluorescence spectrophotometry

Question 5

• begins when a molecule abosorbs light, causing it to promote electrons to a higher energy state
• from singlet ground state promoted to a single excited state

Answer 5

excitation

Question 6

• occurs when the excited state of a molecule returns to its ground state
• involves emitting of photons that has a lower energy and longer wavelength than the absorbed photon

Answer 6

emission

Question 7

• a molecule with fluorescence properties
• absorbs light energy of a specific wavelength and re-emit it at a longer wavelength

Answer 7

fluorophore

Question 8

shows the process involved in creation of an excited electronic singlet state by light absorption and subsequent emission of fluorescence

Answer 8

jablonski diagram

Question 9

• the average time that a fluorophore spends in the excited state depending on the molecule types and tis local environment
• varies from picoseconds to hundreds of nanoseconds depending on the molecule

Answer 9

fluorescence lifetime (FLT)

Question 10

General components of fluorescence spectrophotometry

Answer 10

1. white light source
2. excitation monochromator
3. sample chamber
4. emission monochromator
5. detector

Question 11

a light source that produce a wide range of wavelengths from ultraviolet to infrared

Answer 11

white light source

Question 12

selects the desired wavelength of excitation light, which is focused at the sample position

Answer 12

excitation monochromator

Question 13

houses the cuvette (transparent tube) that is designed to hold samples that contains the analyte

Answer 13

sample chamber

Question 14

• begins when a molecule absorbs light, causing it to promote electrns to a higher energy state
• from a singlet ground state promoted to a single excited state

Answer 14

Excitation

Question 15

• occurs when the excited state of a molecule returns to its ground state
• involves emitting of photons that has a lower energy and longer wavelength than the absorbed photon

Answer 15

Emission

Question 16

application of fluorescence spectrophotometry example

Answer 16

COVID-19 determination in clinical swab samples