Nanostructered Multilayers of Redox Polymers and Enzymes...

Nanostructered Multilayers of Redox Polymers and Enzymes for Molecular

Recognition and Electrical Signal Generation

Ernesto J. CalvoINQUIMAE. Departamento de Quimica Inorganica, Analitica y

Quimica Fisica. Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires, Argentina

BIBLIOGRAPHY

• A. Ulman. Introduction to Thin Films: From Langmuir–Blodgett to Self-Assembly, Academic Press, Boston (1991).

• G. Decher. Science 277, 1232 (1997).

• Decher, G.; Schlenoff, J. B. Multilayer Thin Films: Sequential Assembly of Nanocomposite Materials;Wiley-VCH: Weinheim, 2003.

A.J. Bard, Integrated Chemical Systems, John Wiley & Sons, 1994

INTEGRATED CHEMICAL SYSTEMS

Nanostructured Multilayer Films

Langmuir-Blodgett Films

Langmuir-Blodgett Trough

A stearic acid isotherm

Forces

Electrostatic ≈ 1/r2

Van der Waals ≈1/r6

πA = kT

Molecular Film Transfer to a Surface

Langmuir-Blodgett Films

Hydrophobic SurfaceFormation of a second layer

Hydrophillic surface

Types of LB films

Isotherm of Fatty acid in the water-air interphase

75 100 125 150 175 200

0

10

20

30

40

50

60Pr

essu

re (m

N/m

)

Trough area (cm2)

Fatty acid on water subphase Fatty acid on CdCl2 subphase

16 18 20 22 24 26 28 30 32 34 36-5

0

5

10

15

20

25

30

35

40

Pres

sure

, mN

/m

Molecular area, A2

C18NH2 on water

5 10 15 20 25 30 35 40

0

10

20

30

40

50

Pres

sure

Molecular area

amine pH=9 pH=3 pure water

Effect of Molecular Structure

60 80 100 120 140 160 180-5

0

5

10

15

20

25

30

35

40Pr

essu

re

Molecular area

DODA on water

Transfer of Molecular Layer to a Solid Hydrophobic Surface

0 500 1000 1500 2000 250040

60

80

100

120

140A

rea,

cm

2

Time, Sec

AreaA,cm²

Gil Markovich, C. Patrick Collier,Sven E. Henrichs, Francoise Remacle, Raphael D. Levine, andJames R. Heath*Acc. Chem. Res., 32 (5), 415 -423, 1999

Nanoparticles LB Film