S
1
Supporting Information
Direct Electrochemistry of Endon
uclease III in the Presence an
d Absence of DNA
Alon
A. Gorode
tsky,
Amie K. Boal, Jacque
line K. Barton
*
Division
of Chemistry and Chemical Engi
neering
California Institute of Technol
ogy
Pasadena CA 91
125
jkba
rton@
caltech.edu
Figu
re S1.
CV
of 50
μ
M Endo
III on bare HOPG
at a 20 mV/s scan rate show
ing
the
2+
/1+
coupl
e
. A plot of peak current as a func
tion
of scan rate is inset.
S
2
Figu
re S2
.
SWV
of 50
μ
M Endo
III on
bare HOP
G at 15 Hz show
ing
the 2+
/1+
coupl
e
. An electrode
backfilled with octane show
ing
the loss of the signa
l
is in blue.
Electrode
s have been normalized by their geom
etric surface
areas for clarity.
Figu
re S3
.
CV of 20
0
μ
M Endo
III on bare HOP
G at a 50 mV/s scan rate show
ing
the
3+
/2+
coupl
e
.
Note that bot
h anodi
c and
cathodi
c peaks are obs
erved here.
A.
B.
Figu
re S4
.
CV’s
of 5
0
μ
M Endo
III on
DNA
modi
fied HOPG (A) and
bare HOP
G
(B)
at a 50
mV/s scan rate. B
lank
electrode
s run without
protein
in storage buffer are
show
n
in red
.
The electrode
s show
n in black are identical to the one
s in the text.
Note the
absence of a signa
l on
the b
l
ank
electrode
s.
+
D
N
A
-
5
0
5
0
1
5
0
-
0
.
4
-
0
.
2
0
.
0
0
.
2
0
.
4
0
.
6
P
o
t
e
n
t
i
a
l
(
V
v
s
.
N
H
E
)
Current (nA) in
-
D
N
A
-
1
7
0
-
2
0
1
3
0
-
0
.
4
-
0
.
2
0
.
0
0
.
2
0
.
4
0
.
6
P
o
t
e
n
t
i
a
l
(
V
v
s
.
N
H
E
)
Current (nA) in
S 3