Measurement of concentration of bio-material by using acoustic resonator

Abstract

Over the past several decades, sensing methodology based on vibration principles has been studied extensively. Among the resonance-based sensors, cantilever sensors have significant advantages over other sensors, in terms of fast response time, high sensitivity, high resolution and low cost of fabrication(1). They have had broad applications in the fields of chemistry(2), biotechnology(3), etc. Since the methodology mostly relies on only added mass effect on the resonant frequency(4), improvements of the sensitivity of the cantilever-type sensors are usually realized by shrinking its physical dimension or measuring higher order modes, which can result in the limitations of physical dimension and frequency measurement. In this paper, Helmholtz resonator (HR) filled with fixed fluid and test solution was presented, whose change of resonant frequency can indicate the change of analyte concentration in the test solution. Theoretical derivation of measurement principle and experimental investigation were conducted, by using measurement of glucose concentration in test solution as an example. Results showed higher sensitivity and relatively low frequency range compared to previous resonance based methods. Measurement of practical level of glucose concentration in human blood by using the suggesting HR was discussed, which reveals the possibility of using it as a biosensor.