lecture 1 - craggs Flashcards
what where the two noble prizes in 2008 and 2014 for
creation and development green fluorescent protein
development of super-resolved fluorescent microscopy
what does GFP allow you to do
genetically tag a protein of interest and track it in a cell
what is flourescence
a type of luminescence where emission is at longer wavelength than excitation
pros of fluorescence
very sensitive
background
single molecule detection possible
how fast is absorption
1 fs
how fast is flourescence
1 - 10 ns
what environmental factors influence speed of fluorescence
protonation
conformational motion
rotation
quenching
parts of fluorescence spectrometer
excitation source wavelength selection (excitation filter) sample wavelength selection (emission filter) detector
who invented vibronic transitions
aleksander jablonski
the different levels of vibronic transition
ground state - S0
first excited singlet state - S1
second excited singlet state - S2
first excited triplet state - T1
what is intersystem crossing
moves from S1 to T1
electrons with anti-parallel spin which adds to 0
time scale of phosphoresence
1 micro second to minutes
equation of spin multiplicity
2S + 1
S = sum of all electron spins
two possible spins of electrons
+ or - 1/2
why do vibronic transitions occur
instead of excited molecules moving to different atomic coordinates they only have time for vertical transitions
