A high performance and cost effective biosensor is designed based on a radial contour-mode disk resonator. Filling a dielectric material within the capacitive gap, we can achieve low motional resistance (R(x)) in a cost-effective manner. The motional resistance of the new device is characterized analytically and validated using 3D-multiphysics simulation. Compared with other biosensors, the introduced biosensor may detect the smaller mass changes with mass sensitivity of -74.68 mu m(2)/ng (-1617 Hz/ng). (C) 2011 Elsevier B.V. All rights reserved.