谐振调幅压电石英晶体分子键裂型传感仪的研制

Development of a Biosensor of Resonant Amplitude Modulated Piezoelectric Quartz Crystal for Molecular Bond Rupturing

基于谐振调幅激励压电石英晶体开发了一种分子键裂型传感仪。该传感系统通过数字信号发生器DDS 9854产生频率可调的正弦波,激励9.98 MHz的压电石英晶体,经信号放大滤波后得到谐振频率。通过数控技术调节激励电压实现谐振调幅,以增大石英晶振表面的剪切动量。当调幅到一定程度会导致分子间键断裂,通过调幅电压值测定分子键的强度,可在数分钟内得到晶体表面的结合质量和结合强度的信息。使用了谐振调幅压电石英晶体分子键裂型传感仪检测了不同粒径的氨基纳米磁珠与金电极之间的相互作用,由频率信号得到磁珠在金电极上的结合量。通过不同谐振调幅电压激励石英晶体以甩脱电极表面的磁珠,由激励电压得到不同粒径的氨基纳米磁珠与金电极间的键裂力为2±0.5 nN。本仪器的研制为传感分子间的相互作用提供了一种新技术,可快速检测鉴别键的强度。

A molecular bond-rupturing biosensor based on piezoelectric quartz crystal excited by amplitude modulation resonant sinusoidal wave was developed.In this detection system, the frequency adjustable sinusoidal wave was generated by digital signal generator DDS 9854 to excite the 9.98 MHz piezoelectric quartz crystal.After signal amplifying and filtering, the resonant frequency was obtained by adjusting different excitation voltages by numerical control technology.The resonant amplitude modulation was realized, and the shear momentum on the surface of quartz crystal oscillator was increased.When the amplitude modulation reached a certain extent, the molecular bond would break.Thus, the molecular bond strength could be measured, and the information of the bond quality and bond strength on the crystal surface could be obtained in a few minutes.The interaction between different diameters of nanomagnetic beads and gold electrode was detected by the instrument.The binding amount of the magnetic beads on the gold electrode could be obtained from the frequency signal.The magnetic beads on the surface of the electrode were excited by different resonant amplitures-modulated voltages.The bond rupturing force between the amino nanoparticles and the gold electrode was 2±0.5 nN.The development of this instrument provides a new idea for the technology of non-labeled biosensors, which can quickly detect and monitor the interaction between molecules qualitatively and quantitatively.