Activating piezoelectric crystal surface by silanization for microgravimetric immunobiosensor application.
Biosens Bioelectron
; 11(12): 1199-205, 1996.
Article
in En
| MEDLINE
| ID: mdl-8896324
ABSTRACT
The development of a microgravimetric immunobiosensor using a piezoelectric quartz crystal as a detector requires a stable and reproducible immobilization method for ligand binding. The method of silanization using 3-aminopropyltriethoxysilane (APTES) has been widely used for activating the carrier surface. In the present study, APTES deposition on a piezoelectric crystal surface was studied under various solvent conditions. A fluorescence method, using fluorescence isothiocyanate as a dye, was demonstrated for the quantification of amino groups on the silanized piezoelectric crystal surface. The optimum binding conditions of APTES deposition on a piezoelectric crystal surface were incorporated for the covalent immobilization of protein on the crystal surface in developing a stable and sensitive microgravimetric immunobiosensor. Determination of immunoglobulin G (IgG) concentration was performed using APTES modified piezoelectric crystals coated with protein G. The resonant frequency shift, resulting from the formation of protein G-IgG complex on the crystal surface, correlated with the concentration of IgG in the range 10 ng/ml to 0.1 mg/ml. The APTES modified, protein G coated crystal were found to be quite stable and did not show a significant loss of sensitivity even after 12 weeks of storage at 4 degrees C in a desiccator.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Immunoglobulin G
/
Biosensing Techniques
Language:
En
Journal:
Biosens Bioelectron
Journal subject:
BIOTECNOLOGIA
Year:
1996
Document type:
Article
Affiliation country: