Modeling the response of a quartz crystal microbalance under the specific adsorption of microbubbles

Abstract

Targeted microbubbles can accumulate in the targeting site via a biochemical reaction. We propose a system for evaluating the accumulation of the bubbles using a quartz crystal microbalance (QCM) as the thickness shear-mode resonator. We derive the formula of the electrical admittance of QCM for the load of bubbles by modeling the reaction force generated by the specifically adsorbed bubbles. The bubble-load model enabled the calculation of the number density of the adsorbed bubbles on the QCM surface. A comparison with experimental results showed that the proposed system yields the possibility of quantitatively estimating the number density. This system will help us to develop new targeted microbubbles.