Sequential Detection of Immunoglobulin G via Nonspecific Adsorbed Staphylococcal Protein A Using PDMS Quartz Crystal Microbalance Sensor PDMS 水晶振動子センサを用いた非特異吸着プロテイン A に よる免疫グロブリン G の連続捕捉

The frequency shift, relative to the resonance frequency in the case of water, as a function of liquid relative permittivity is shown in Fig. 3. The LFE sensor exhibits a good sensitivity to the relative permittivity, about 13 times as high as the QCM sensor. Figure 4 depicts the frequency shift as a function of liquid electrical conductivity. For the LFE sensor, the sensing range is about 4 times as high as the QCM sensor. The frequency drop saturates finally at about -5.75 kHz, over 125 times as high as the QCM sensor. Besides, we can find a turning point at around 0.1 S/m. This phenomenon also appears in the experiment of Ref [2]. The displacement fields reveal that a mode conversion occurs at this turning point. The displacement field alters from an in-phase shear motion in a slightly eccentric position to an out-of-phase shear motion under the two LFE electrodes.