silicon and dichlorodimethylsilane

In the development of biosensors, the immobilization of biomolecules at interfaces played a crucial role. The feasibility of using 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde (Glu) to modify silicon surface to immobilize covalently protein for immunoassay with the biosensor based on imaging ellipsometry was investigated. The higher density and stability of human IgG layer could be obtained on the silicon surface modified with APTES and Glu than that on the silicon surface modified with dichlorodimethylsilane (DDS). The human IgG molecules immobilized covalently on APTES-Glu surface bound more anti-IgG molecules than that on DDS surface, which indicated that the human IgG molecules could maintain higher binding capability on APTES-Glu surface. Tween 20 was able to block the undesirable adsorption on APTES-Glu surface, and also enhanced the recognition between human IgG and its antibody on both APTES-Glu and DDS surfaces. The combination of this protein covalent immobilization and the biosensor has the potential to be developed into a fast, simple immunoassay technique.

Topics: Antibody Affinity; Biosensing Techniques; Glutaral; Humans; Immobilization; Immunoassay; Immunoglobulin G; Propylamines; Protein Binding; Silanes; Silicon; Surface Properties

The feasibility of using protein A to immobilize antibody on silicon surface for a biosensor with imaging ellipsometry was presented in this study. The amount of human IgG bound with anti-IgG immobilized by the protein A on silicon surface was much more than that bound with anti-IgG immobilized by physical adsorption. The result indicated that the protein A could be used to immobilize antibody molecules in a highly oriented manner and maintain antibody molecular functional configuration on the silicon surface. High reproducibility of the amount of antibody immobilization and homogenous antibody adsorption layer on surfaces could be obtained by this immobilization method. Imaging ellipsometry has been proven to be a fast and reliable detection method and sensitive enough to detect small changes in a molecular monolayer level. The combination of imaging ellipsometry and surface modification with protein A has the potential to be further developed into an efficient immunoassay protein chip.

Topics: Animals; Antibodies, Anti-Idiotypic; Biosensing Techniques; Diagnostic Imaging; Goats; Humans; Immunoglobulin G; Protein Array Analysis; Silanes; Silicon; Staphylococcal Protein A

Group specific component (GC) band patterns of sensitive blood samples may be altered by Repel-Silane. Alterations occur when isoelectric focusing is performed with LKB Immobiline DryPlates rehydrated in a reswelling cassette using Repel-Silane as a hydrophobic additive. In two cases Repel-Silane converted common GC subtypes into apparent rare types.

Topics: Blood Grouping and Crossmatching; Humans; Isoelectric Focusing; Silanes; Silicon; Vitamin D-Binding Protein