CONFOCOR
3
ConfoCor 3
Models
Carl Zeiss
02/2010 M60-1-0025
e
61
Blinking is based on the phenomenon that the electron distribution over conjugated systems can change
in dependence on the local environment, for example changes in the pH, which will lead to molecules in
a bright and dim or dark state. It is therefore a kinetic process that can be described in the following way
with the following relations:
D
B
R
F
k
k
⎯
⎯
⎯ →
←
;
(7f)
R
F
b
k
k
+
=
1
τ
(7g)
(
)
(
)
2
2
2
)
(
D
R
B
F
R
F
D
B
R
F
b
k
k
k
k
k
k
T
η
η
η
η
⋅
+
⋅
⋅
+
−
⋅
⋅
=
with the constraint
D
B
η
η
>
(7h)
with B and D representing the brighter and darker states, k
F
and k
R
the forward and backward reaction
rates and
η
B
and
η
D
the emission yields or molecular brightness of molecule species (D or B) in Hz or the
relative dimensionless brightness. In case, where darker state is completely dark (
η
D
=0), equation 7h
simplifies to
R
F
R
b
k
k
k
T
+
=
(7i)
Note that Blinking is referred to a process that does not lead to a covalent modification in the chemical
bonds. If covalent changes occur the process is referred to as Flickering, which is formally treated in the
same way.
C.3 Dependent triplet and blinking
In this case the terms are just representatives for two dependent bunching terms that are linked by
addition (double exponential term). Note that the triplet fraction, if present, could be potentially fitted to
either of the terms.
)
1
(
)
(
2
1
2
2
1
1
t
t
e
T
T
e
T
T
G
t
τ
τ
τ
τ
τ
−
−
⋅
+
−
⋅
+
−
=
not
normalized
(7j)
)
1
1
(
)
(
2
1
2
1
2
1
T
T
e
T
e
T
G
t
t
t
−
−
⋅
+
⋅
+
=
−
−
τ
τ
τ
τ
τ
normalized
(7k)
where T
1
and T
2
are the fractions of molecules in the triplet state, and
τ
t1
and
τ
t2
the triplet exponential
decay times.
T
1
, T
2
,
τ
t1
and
τ
t2
are all fitted parameters.
