Wingqvist G, Anderson H, Lennartsson C, Weissbach T, Yantchev V, Spetz A Lloyd
Division Solid State Electronics, Angstrom Laboratory, Uppsala University, Uppsala, Sweden.
Biosens Bioelectron. 2009 Jul 15;24(11):3387-90. doi: 10.1016/j.bios.2009.04.021. Epub 2009 Apr 23.
The IC-compatible thin film bulk acoustic resonator (FBAR) technology has made it possible to move the thickness excited shear mode sensing of biological layers into a new sensing regime using substantially higher operation frequencies than the conventionally used quartz crystal microbalance (QCM). The limitations of the linear range set by the film resonance using viscoelastic protein films are here for the first time addressed specifically for FBARs operating at 700 MHz up to 1.5 GHz. Two types of protein multilayer sensing were employed; one utilizing alternating layers of streptavidin and biotinated BSA and the other using stepwise cross-linking of fibrinogen with EDC/NHS activation of its carboxyl groups. In both cases the number of protein layers within the linear regime is well above the number of protein layers usually used in biosensor applications, further verifying the applicability of the FBAR as a biosensor. Theoretical calculations are also presented using well established physical models to illustrate the expected behavior of the FBAR sensor, in view of both the frequency and the dissipation shifts.
与集成电路兼容的薄膜体声波谐振器（FBAR）技术，使得利用比传统使用的石英晶体微天平（QCM）高得多的工作频率，将生物层的厚度激发剪切模式传感带入一个新的传感领域成为可能。本文首次专门针对工作在700兆赫兹至1.5吉赫兹的FBAR，探讨了使用粘弹性蛋白质膜时由薄膜共振设定的线性范围的局限性。采用了两种类型的蛋白质多层传感；一种利用链霉亲和素和生物素化牛血清白蛋白的交替层，另一种利用纤维蛋白原与通过其羧基的EDC/NHS活化进行逐步交联。在这两种情况下，线性范围内的蛋白质层数都远高于生物传感器应用中通常使用的蛋白质层数，进一步验证了FBAR作为生物传感器的适用性。还使用成熟的物理模型进行了理论计算，以说明FBAR传感器在频率和耗散偏移方面的预期行为。
