基于超材料的生物分子溶液快速免标签检测技术研究

发布时间：2019-03-27 11:37

【摘要】：传统射频生物传感方案中,传感器件只能检测干燥样本。对细胞等具有生物活性的生物大分子进行烘干处理后,生物活性降低,其电特性发生改变,从而影响最终检测结果。为了在微波频段灵敏检测出生物分子溶液或液体的介电特性,本文提出基于对称超材料元件作为谐振结构的射频生物传感器。首先,介绍了基于超材料结构的射频生物传感器的研究背景。其次,阐述谐振型生物传感器的工作原理、谐振型超材料传输线设计方案及谐振结构和生物溶液结合过程。详细描述有效介质、半波长谐振器、左手介质和超材料传输线四个方面的生物传感器设计的理论基础。通过开环谐振器(split-ring resonator,SRR)或互补开环谐振器(complementary split-ring resonator,CSRR)的纯谐振方法或混合方法耦合可得到多种不同类型的传输线。再次,提出了基于开环谐振器(nested split-ring resonator,nSRR)结构的生物传感器设计方案。仿真验证了被检测溶液的介电常数、厚度及覆盖位置对生物传感器的影响。最后,阐明了新型生物传感器的制备和测量校准过程。生物传感器裸片谐振频率的测试结果与相应的仿真结果相符,从而验证了仿真结果的正确性。开展了聚二甲基硅氧烷(Polydimethysiloxane,PDMS)液体样本测试实验,并与相应的仿真结果进行了比较。综上所述,本文利用阻抗匹配方法,设计出基于对称超材料元件作为谐振结构的射频生物传感器,该生物传感器可用于免标签的生物分子溶液快速检测。生物传感器裸片的实验测试结果与仿真结果符合较好,验证了理论以及设计方案的正确性。通过PDMS液体样本测试实验,初步证明了生物传感器可以通过测试添加液体前后谐振频率的变化,推测被测生物分子液体或溶液的介电特性。
[Abstract]:In traditional RF biosensors, only dry samples can be detected by sensors. After drying the biological macromolecules, such as cells, the biological activity decreased and its electrical properties changed, thus affecting the final detection results. In order to detect the dielectric properties of biomolecular solution or liquid sensitively in microwave frequency band, a novel RF biosensor based on symmetric supermaterial as resonant structure is proposed in this paper. Firstly, the research background of RF biosensor based on supermaterial structure is introduced. Secondly, the working principle of resonant biosensor, the design scheme of resonant supermaterial transmission line and the process of combining resonant structure with biological solution are described. The theoretical basis of biosensor design in effective medium, half-wavelength resonator, left-handed medium and supermaterial transmission line is described in detail. Different types of transmission lines can be obtained by coupling the pure resonant method or the hybrid method of open loop resonator (split-ring resonator,SRR) or complementary open loop resonator (complementary split-ring resonator,CSRR). Thirdly, a design scheme of biosensor based on open-loop resonator (nested split-ring resonator,nSRR) is proposed. The effects of dielectric constant, thickness and cover position on the biosensor are verified by simulation. Finally, the preparation and measurement calibration process of the new biosensor are expounded. The test results of the resonance frequency of the biosensor are in good agreement with the corresponding simulation results, which verify the correctness of the simulation results. The liquid samples of polydimethylsiloxane (Polydimethysiloxane,PDMS) were tested and compared with the corresponding simulation results. In summary, using impedance matching method, a novel RF biosensor based on symmetric supermaterial as resonant structure is designed. The biosensor can be used for fast detection of biomolecular solution without label. The experimental results are in good agreement with the simulation results, which verify the correctness of the theory and the design scheme. The experiment of PDMS liquid sample shows that the biosensor can predict the dielectric properties of the biomolecular liquid or solution by testing the change of resonance frequency before and after adding liquid.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212.3

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