This article investigates the impact of incorporating silica nanoparticles of varying diameters in label free impedance immunosensor. It has been observed that even if the surface area improvement has been adjusted to be similar for all the diameters, the sensitivity is enhanced by five times at a particular diameter of 100 nm due to the optimum combination of intersection with electric field lines and surface convexity. This study has enabled the detection of 0.1 fM Hep-B surface antigen with a reliable sensitivity of around 75%. Further, it has been observed that the SNR corresponding to 0.1 fM is 20 dB only for 100 nm particle. This SNR is comparable to a recent report on Hep-B virus detection but the limit of detection in the proposed sensor is lowered by more than three orders of magnitude.

中文翻译：

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基于二氧化硅纳米颗粒的阻抗免疫传感器提高灵敏度的实验和有限元分析

本文研究了在无标记阻抗免疫传感器中加入不同直径的二氧化硅纳米粒子的影响。已经观察到，即使已将所有直径的表面积改进调整为相似，由于与电场线的交叉和表面凸度的最佳组合，灵敏度在 100 nm 的特定直径处提高了五倍. 这项研究能够以大约 75% 的可靠灵敏度检测 0.1 fM Hep-B 表面抗原。此外，已经观察到，信噪比对应于 0.1 fM 仅为 100 nm 粒子的 20 dB。这个信噪比 与最近关于 Hep-B 病毒检测的报告相当，但所提议的传感器的检测限降低了三个数量级以上。