A semi-empirical model was applied to estimate the frequency shift of a shear-horizontal surface-acoustic-wave (SH-SAW) biosensor for detecting a disease-related biomarker antigen transferrin receptor (CD71) in the sample. In the simulation to investigate its sensitivity, a shift of the SH-SAW resonant frequency occurred by applying an incremental surface mass density change on the surface. The semi-empirical model was proposed and developed by using the experimental and numerical results to relate the concentration of the biomarker to the frequency shift. Results indicated that the thickness of the SiO2 guiding layer affects the sensitivity of SH-SAW sensing, and the dependence is non-monotonically. The SH-SAW sensor was used for specific detection of biotin at a varied concentration. With the concentration of the targeted antigen in the range 0.4 ∼4.2 μg/mL, a typical exponential relation was found between the quantitative target and the frequency shift. Measurement results showed that the mass-loading effect of the antibody-antigen has a reliable response with a sensitivity of 0.94 kHz/(μg/mL). Effects of the sample flow rate on the antigen- antibody interaction and thus the frequency shift of the SH-SAW sensor were also evaluated. It is demonstrated that the proposed model provides a useful approach to analyze effectively the frequency shift dependence on the concentration and the flow rates of sensed molecules in a flow-type SH-SAW sensor.

中文翻译：

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剪切水平表面声波生物传感器上转铁蛋白受体CD71的检测。

应用半经验模型来估计用于检测样品中与疾病相关的生物标志物抗原转铁蛋白受体（CD71）的剪切-水平表面声波（SH-SAW）生物传感器的频移。在研究其灵敏度的模拟中，通过在表面上应用递增的表面质量密度变化，发生了SH-SAW谐振频率的偏移。利用实验和数值结果提出并开发了半经验模型，以将生物标志物的浓度与频移联系起来。结果表明，SiO2引导层的厚度会影响SH-SAW感应的灵敏度，并且其依赖性是非单调的。SH-SAW传感器用于检测浓度不同的生物素。靶向抗原的浓度在0范围内。在4〜4.2μg/ mL范围内，定量目标与频移之间存在典型的指数关系。测量结果表明，抗体-抗原的质量负载效应具有可靠的响应，灵敏度为0.94 kHz /（μg/ mL）。还评估了样品流速对抗原-抗体相互作用的影响，并因此评估了SH-SAW传感器的频率偏移。结果表明，所提出的模型提供了一种有用的方法，可以有效地分析频移对流量型SH-SAW传感器中所检测分子的浓度和流速的依赖性。94 kHz /（微克/毫升）。还评估了样品流速对抗原-抗体相互作用的影响，并因此评估了SH-SAW传感器的频率偏移。结果表明，所提出的模型提供了一种有用的方法，可以有效地分析频移对流量型SH-SAW传感器中所检测分子的浓度和流速的依赖性。94 kHz /（微克/毫升）。还评估了样品流速对抗原-抗体相互作用的影响，并因此评估了SH-SAW传感器的频率偏移。结果表明，所提出的模型提供了一种有用的方法，可以有效地分析频移对流量型SH-SAW传感器中所检测分子的浓度和流速的依赖性。