INVESTIGADORES
CALVO Ernesto Julio
artículos
Título:
The structure of Layer-by-layer self-assembled glucose oxidase and Os(bpy)2Cl Py CH2 NH-Poly(allylamine) multilayers: Ellipsometric and Quartz Crystal Microbalance Studies
Autor/es:
E.S. FORZANI,; M. OTERO,; M.A. PÉREZ,; LÓPEZ TEIJELO, M.; ERNESTO JULIO CALVO
Revista:
ANALYTICAL CHEMISTRY
Referencias:
Año: 2002 p. 4020 - 4020
ISSN:
0003-2700
Resumen:
We describe quartz crystal electroacoustic admittance
studies in thickness shear mode resonators loaded with
self-assembled multilayers composed of alternate layers
of glucose oxidase (GOx) and poly(allylamine) covalently
attached to [Os(bpy)2ClPyCOH]-, (PAH-Os), deposited
on a 3-mercaptopropanesulfonic acid (MPS)-modified
gold on the quartz crystal. The complex acoustic impedance
parameters, RS and XLS of a lumped-element
Butterworth-Van Dyke (BVD) resonator have been determined
for organized thin films of different thickness
obtained by varying the number of enzyme layers, n, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.Gn, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GRS and XLS of a lumped-element
Butterworth-Van Dyke (BVD) resonator have been determined
for organized thin films of different thickness
obtained by varying the number of enzyme layers, n, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.Gn, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.G2ClPyCOH]-, (PAH-Os), deposited
on a 3-mercaptopropanesulfonic acid (MPS)-modified
gold on the quartz crystal. The complex acoustic impedance
parameters, RS and XLS of a lumped-element
Butterworth-Van Dyke (BVD) resonator have been determined
for organized thin films of different thickness
obtained by varying the number of enzyme layers, n, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.Gn, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GRS and XLS of a lumped-element
Butterworth-Van Dyke (BVD) resonator have been determined
for organized thin films of different thickness
obtained by varying the number of enzyme layers, n, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.Gn, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.G-Van Dyke (BVD) resonator have been determined
for organized thin films of different thickness
obtained by varying the number of enzyme layers, n, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.Gn, in
(PAH-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.GXLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f on the order of 106 Pa. The films became viscoelastic upon oxidation to Os(III), resulting in an increase of RS
and XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.XLS in the oxidized state with the number of (PAHOs)(
GOx) bilayers due to film swelling and an increase
in the shear moduli during oxidation.G-Os)n(GOx)n structures. The ellipsometric film
thickness and mass for dry enzyme multilayer films and
films in contact with water were evaluated, and the average
film density was estimated. By combination of the estimated
film thickness and density, the expression for the
surface mechanical impedance of the lumped-element
modified resonator (Granstaff and Martin model), and the
liquid density and viscosity, we simulate the layer-by-layer
film growth on the basis of the measured electroacoustic
impedance. The complex impedance XLS and RS increase
with film thickness and the enzyme films can be regarded
as acoustically thin in the reduced state for films thinner
than 600 nm. We have also measured electroacoustic
parameters for PAH-Os/GOx self-assembled multilayers
under electrochemical perturbation in a buffer electrolytic
solution. The electrostatically self-assembled multilayers
behaved as lossy viscoelastic films at 10 MHz with G¢f and G¢¢f