An immunosensor: Immobilization of anti-HBs antibody on glow-discharge treated piezoelectric quartz crystal for HBs-AG detection

In this study, an immunosensor with a piezoelectric quartz crystal was deve loped. An oscillator system, in order to measure the frequency shifts cause d by the increase of mass on the piezoelectric crystal, was used. The surfa ces of the quartz crystals were treated by a glow-discharge technique utili zing ethylene diamine monomer to substitute amino groups on the surface of the crystal. These groups were activated by a bifunctional cross-linker, gl utaraldehyde, to immobilize an antibody (so called anti-HBs). Optimum condi tions for each of the modification steps for application on the quartz crys tal surfaces were established and the results were represented for optimum time, pH and concentration. The sensor was calibrated at optimum conditions for HBs-Ag detection.