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1990
Conference Paper
Titel
A quartz crystal biosensor for measurment in liquids
Abstract
The detection of anti-HIV antibodies by means of synthetic HIV-peptide immobilized on a piezoelectric quartz sensor is demonstrated. The measurement set-up consists of an oscillator circuit, a suitably modifies AT-cut thickness-shear-mode quartz crystal with gold electrodes, which is housed into a special reaction vessel, and a computer controlled frequency counter for the registration of the measured frequency values. The quartz crystal is adapted for a steady operation in liquids at a frequency of 20 MHz. The oscillator reaches in PBS solution a stability of about 0.5 Hz within 10 minutes and about 30 Hz within 1 hour. The frequency shift due to the adsorption of various proteins to the uncoated sensor suface has been investigated. It can be shown that a stable adsorptive binding of proteins to an oscillating gold surface is feasible and can be used for the immobilization of a receptor-layer (e.g. HIV-peptide). Specific binding of the anti-HIV monoclonal antibody to the HIV-peptide i mmobilized on the quartz sensor is demonstrated. Control experiments show, however, additional unspecific binding. According to the experiments, the Sauerbrey formula gives a sufficiently accurate value for the decrease of the resonant frequency due to adsorption or binding of macromolecular proteins on the quartz crystal surface.
Konferenz
Language
English