Study of hydroxy-naphthoquinone ultra-thin films obtained by diazonium electroreduction: towards design of bio-sensitive electroactive interfaces Gregory March, Steeve Reisberg, Benoit Piro, Minh-Chau Pham, Claire Fave, Vincent Noel*
Laboratoire ITODYS (Interfaces, Traitements, Organisation et Dynamique des Systèmes), UMR 7086, Université Denis Diderot-Paris 7, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
Corresponding author: Dr. V. Noel: Tel: 033 157277226; Fax: 033 157277263; e-mail:
[email protected] S1
SI 1. Cyclic voltammograms of a bare Au electrode in 10-1 M Et4NBF4 acetonitrile solution containing 10-3M of (dashed line) JUG and (plain line) JUGNH2 ; scan rate = 100 mV.s-1.
0,35 0,30
Absorbance
0,25
JUGNH2
0,20
JUGNH2 + HClO4 0,15
JUGNH2 + HClO4 + NaNO2
0,10 0,05 0,00 -0,05 200
300
400
500
600
700
800
λ (nm)
SI 2. UV spectra of the JUGNH2 solution in (black line) ACN and (gray line) 0.1 M HClO4 (dotted line) 0.1 M HClO4 + 1 eq. NaNO4
S2
% Transmittance
1 0 0 ,1
1 0 0 ,0
9 9 ,9
9 9 ,8
4500
4000
3500
3000
2500
2000
W a v e n u m b e r (c m
1500 -1
1000
500
)
SI 3. IRRAS spectrum of JUGφ on Au plates obtained after 2 cycles (50 mV.s-1) in diazonium solution
SI 4. XPS survey spectrum of JUGφ on Au plates obtained after two deposition cycles.
S3
S2p
C1s
C1s
O1s
O1s
N1s
Na1s
Cl2p
(168 eV)
(285 eV)
(286.94 eV)
(531.8 eV)
(533.28 eV)
(400 eV)
(1072 eV)
(208 eV)
5.1
60.6
13.8
3.1
14
1.8
0.9
0.8
SI 5. High-resolution XPS spectra Apparent surface atomic ratio (in at.%) of JUGΦ obtained by two 50 mV.s-1 scans
S4
(a)
(b)
SI 6. XPS spectra (plain line), deconvolution (dashed lines) and residual plot (dotted line) for (a) C1s and (b) O1s. Bare Electrode 800000 700000
Counts / s
600000 500000 400000
JUGΦ
300000 200000 100000 0 90
88
86
84
82
before
and
Binding Energy (eV)
SI
7.
Au4f
high-resolution
XPS
spectra
after
modification
S5
t/s
t/s 0
5
10
15
20
25
0
30
50
100
150
200
250
300
0
a
a b
b
-5
I / µA
I / µA
-5
0
-10
-10
-15 -15
-20 -20
(A)
(B)
SI 8. Chronoamperogram for an Au electrode in the diazonium solution for different tdep (A) 30s and (B) for tdep=300 s; Edep (a) -0.2 V, (b) -0.5 V. 0,3 0,25
∆ Ep (V)
0,2 0,15 0,1 0,05 0 0
50
100
150
200
250
300
350
t (s )
SI 9. Variation of ∆Ep with tdep for Edep ( ) -0.5 V and (▲) -0.2 V.
S6
12 10 8
I (µA)
6 4 2 0 -2 -4 -6 -8 -1,0
-0,8
-0,6
-0,4
-0,2
0,0
0,2
0,4
0,6
0,8
E/V
SI 10. CV scan of JUGΦ film in 10-3 M K4Fe(CN)6 in PBS solution at 100 mV.s-1 obtained for tdep = 5 s and Edep (grey) -0.5 V and (black) -0.2 V. (dashed line) CV scan of bare Au electrode.
SI 11. CV scan of JUGΦ film in 10-3 M K4Fe(CN)6 in PBS solution at 100 mV.s-1 obtained for tdep = 60 s and (black line) Edep=-0.5 V and (grey line) -0.2 V. (dashed line) CV scan of bare Au electrode.
S7
g
3
f
e
d
c
2
b
a
I (µA)
1
0
-1
-2
-3 -1,0
-0,8
-0,6
-0,4
-0,2
0,0
E (V/ECS)
SI 12. CV scan of JUGΦ film in various buffer solutions at pH: (a) 3.66, (b) 6.46, (c) 8.4, (d) 9.41, (e) 10.31, (f) 11.84 and (g) 13, v = 100 mV.s-1
0 -0,1
E°' (V)
-0,2 -0,3
y = -0,053x + 0,1475 2 R = 0,9961
-0,4 -0,5 -0,6 -0,7 0
2
4
6
8
10
12
14
pH
SI 13. Variation of E°’ with pH 0,2 0 -2
-1
0
1
2
3
4
Ep (V)
-0,2
Epa -0,4
Epc
-0,6 -0,8 -1
.
log v
SI 14. Variation of peak potentials with log v at pH 7.4 for a JUGΦ film obtained at Edep = -0.2 V, 30 s. S8
