Nanoporous Anodic Alumina Surface Modification by Electrostatic, Covalent, and Immune Complexation Binding Investigated by Capillary Filling
2018-03-06T00:00:00Z (GMT)
by
The
fluid imbibition-coupled laser interferometry (FICLI) technique has
been applied to detect and quantify surface changes and pore dimension
variations in nanoporous anodic alumina (NAA) structures. FICLI is
a noninvasive optical technique that permits the determination of
the NAA average pore radius with high accuracy. In this work, the
technique is applied after each step of different surface modification
paths of the NAA pores: (i) electrostatic immobilization of bovine
serum albumin (BSA), (ii) covalent attachment of streptavidin via
(3-aminipropyl)-triethoxysilane and glutaraldehyde grafting, and (iii)
immune complexation. Results show that BSA attachment can be detected
as a reduction in estimated radius from FICLI with high accuracy and
reproducibility. In the case of the covalent attachment of streptavidin,
FICLI is able to recognize a multilayer formation of the silane and
the protein. For immune complexation, the technique is able to detect
different antibody–antigen bindings and distinguish different
dynamics among different immune species.