Development of a biosensor based on a piezoelectric film

Most gravimetric biosensors use thin piezoelectric quartz crystals (quartz crystal microbalance, QCM), either as resonating crystals, or as bulk/surface acoustic wave (SAW) devices. A system is described in which acoustic waves are launched in very thin (25 microns) polymer films to produce an oscillatory resonant device. A theoretical equation for this system is almost equal to the Sauerbrey equation used in the QCM method. A system using a PVDF film was tested in protein detection. Results showed that the PVDF film can act has a microbalance. Currently, a new system using a PVDF/Immobilon-P/PVDF film, to be used in protein detection, is being tested. Results for the PVDF system and current work with the new system are presented.