A simple model is designed for an inductive immunosensor in which the magnetic particles are attached to the bioreceptors to form a sandwich on the surface of an inductor. The inductor consists of a coil covered on a silicon oxide wafer. The coil comprises 250 turns of a planar gold wire, which is approximately 200 nm thick and 392 mm long, placed in a circle with a diameter of 2 mm. The model is well characterised by controlling the geometrical and electrical parameters and also the permeability of the magnetic material. To evaluate the feasibility of the model for virus monitoring, a novel inductive immunosensor is designed and for the first time applied for the detection of hepatitis B surface antigen (HBsAg). At first, Fab′ segment of primary anti-HBsAg is immobilised on the coil. Then, the coil is exposed to HBsAg and the complex is introduced to a secondary antibody conjugated with magnetic particles to form an immune-sandwich. Finally, the influence of magnetic particles on the coil inductance is recorded and used as a signal for HBsAg detection. The magnetic inductive immunosensor showed specific responses toward HBsAg with the detection limit of 1 ng mL−1, linear range of 1 to 200 ng mL−1, and a sensitivity of 6 × 10−4 mL ng−1. The experimental results showed a very good agreement with simulation data indicating the compatibility of sensor sensitivity to the expected theoretical values. Graphical abstract Graphical abstract

中文翻译：

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设计用于病毒监测的磁感应微电极：乙型肝炎病毒的建模和可行性

一个简单的模型是为感应免疫传感器设计的，其中磁性粒子附着在生物受体上，在感应器的表面形成三明治。电感器由覆盖在氧化硅晶片上的线圈组成。该线圈包括 250 匝平面金线，其厚度约为 200 纳米，长 392 毫米，放置在直径为 2 毫米的圆圈中。该模型通过控制几何和电气参数以及磁性材料的磁导率来很好地表征。为了评估病毒监测模型的可行性，设计了一种新型感应免疫传感器，并首次应用于乙型肝炎表面抗原（HBsAg）的检测。首先，初级抗 HBsAg 的 Fab' 段被固定在线圈上。然后，将线圈暴露于 HBsAg，并将复合物引入与磁性颗粒结合的二抗中，形成免疫夹心。最后，记录磁性粒子对线圈电感的影响，并将其用作 HBsAg 检测的信号。磁感应免疫传感器对 HBsAg 显示出特异性响应，检测限为 1 ng mL-1，线性范围为 1 至 200 ng mL-1，灵敏度为 6 × 10-4 mL ng-1。实验结果与模拟数据非常吻合，表明传感器灵敏度与预期理论值的兼容性。图形摘要图形摘要 磁性粒子对线圈电感的影响被记录下来并用作HBsAg检测的信号。磁感应免疫传感器对 HBsAg 显示出特异性响应，检测限为 1 ng mL-1，线性范围为 1 至 200 ng mL-1，灵敏度为 6 × 10-4 mL ng-1。实验结果与模拟数据非常吻合，表明传感器灵敏度与预期理论值的兼容性。图形摘要图形摘要 磁性粒子对线圈电感的影响被记录下来并用作HBsAg检测的信号。磁感应免疫传感器对 HBsAg 显示出特异性响应，检测限为 1 ng mL-1，线性范围为 1 至 200 ng mL-1，灵敏度为 6 × 10-4 mL ng-1。实验结果与模拟数据非常吻合，表明传感器灵敏度与预期理论值的兼容性。图形摘要图形摘要