Scanning angle reflectometry (SAR) is used to investigate the structure of antigen/antibody layers deposited on a silica surface. The reflectivity curves are analyzed by the means of the optical invariants, which permits the determination of three structural characteristic parameters for the layer. A new invariant is constructed that yields information about the repartition of mass in the layer and thus goes beyond the usual uniform layer model. In our case, this model does not hold: the layer appears to be denser away from the adsorbing silica surface than near that surface.

1.
J. A.
Henderson
et al.,
Macromolecules
26
,
65
(
1993
);
A.
Karim
et al.,
Phys. Rev. Lett.
73
,
3407
(
1994
).
2.
R. M. A. Azzam and N. M. Bashara, Ellipsometry and Polarized Light (North-Holland, Amsterdam, 1989).
3.
M.
Malmsten
,
J. Colloid Interface Sci.
166
,
333
(
1994
).
4.
See, for example, the journal volume consecrated to the subject Thin Solid Films 233, (1993).
5.
J. Lekner, Theory of Reflection (Martinus Nijhoff Publishers, Dordrecht, 1987).
6.
D.
Bedeaux
and
J.
Vlieger
,
Physica
67
,
55
(
1973
).
7.
M. T.
Haarmans
and
D.
Bedeaux
,
Thin Solid Films
258
,
213
(
1995
).
8.
Notations of Haarmans and Bedeaux (see Ref. 7).
9.
J. D. Jackson, Classical Electrodynamics, 2nd ed. (Wiley, New York, 1975).
10.
P.
Schaaf
,
Ph.
Déjardin
, and
A.
Schmitt
,
Revue Phys. Appl.
21
,
741
(
1986
);
P.
Schaaf
,
Ph.
Déjardin
, and
A.
Schmitt
,
Langmuir
3
,
1131
(
1987
);
E. K.
Mann
et al.,
J. Phys. Chem.
99
,
790
(
1995
).
11.
P. R. Bevington, Data Reduction and Error Analysis for the Physical Sciences (McGraw-Hill, New York, 1969).
12.
Ph.
Huetz
et al.,
Langmuir
11
,
3145
(
1995
).
13.
L. Heinrich et al., Lamgmuir (in press).
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