Hydroxynaphthoquinone Ultrathin Films Obtained by Diazonium

Mar 31, 2010 - ... Syste`mes), UMR 7086, Université. Denis Diderot-Paris 7, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baıf, 75205 Paris Cedex 13, ...
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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