| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 870112 | Biosensors and Bioelectronics | 2007 | 8 Pages |
A factor limiting the detection time of biological particles using a quartz crystal microbalance (QCM) system is the kinetics of the particles arriving within the sensing region of the crystal surface. A device has been developed which, for the first time, combines ac electro-kinetic particle manipulation with simultaneous acoustic sensing on an electrode surface. We have termed this device a dielectrophoretic quartz crystal microbalance (DEP-QCM). Particles within the system are rapidly driven by electro-hydrodynamic and dielectrophoretic forces on to the crystal surface. Frequency shift analysis of mass-loaded DEP-QCM, induced by fluid motion, has shown significant improvements in rates of detection based on particle concentration, with steady-state responses established by a factor of five times faster than other quartz crystal microbalance surface loading techniques described in the literature. Comparisons of the static fluid case for QCM devices revealed that particles with a concentration of less than 108 nano-spheres/ml could not be detected within a 1 h time period when allowed to sediment.
