A biomolecule compatible electrical model of microimpedance affinity biosensor for sensitivity improvement in cell detection
A biomolecule compatible electrical model of microimpedance affinity biosensor for sensitivity improvement in cell detection
复制标题
用于提高细胞检测灵敏度的微阻抗亲和生物传感器的生物分子兼容电模型
DOI：
10.1016/j.sna.2009.11.031
复制
发表时间：
2010
影响因子：
4.6
通讯作者：
R. D. Das
中科院分区：
文献类型：
--
作者：
C. Roychaudhuri;R. D. Das
使用叉指电极的微阻抗亲和生物传感器被广泛用于无标记和快速检测细菌分子。为了提高这种传感器的灵敏度，需要通过适当的定量来最大化针对所施加的输入浓度捕获的抗体固定和细菌，并且还优化电极几何形状以实现最大信噪比。在本文中，生物分子兼容的电气模型已被开发，量化的固定化抗体和捕获的细菌的数量通过简单的计算从阻抗谱的结果，这是可比的精度通过常规的耗时，有时昂贵的生化方法，也可以估计与每个生物分子的电极阻抗。将该模型应用于金电极上抗体-抗原结合法检测大肠杆菌K12菌，以PBS为背景溶液。在这种情况下，对于输入浓度为103 CFU/ml和106 CFU/ml的金表面上的抗体固定化和细菌捕获的实际数量的定量估计分别与常规的光密度法和放射性标记法相匹配。在提取每个生物分子的电极阻抗后，推导出几何参数与输出信号之间的定量关系，并将传感器几何形状对该生物传感器灵敏度的影响与最近报道的相同系统的实验结果相匹配。因此，所提出的模型能够定量估计的抗体固定和细菌捕获和定量预测的最佳几何形状的最大灵敏度，消除了试错实验的需要。这将导致一个快速和成本效益的方法，提高性能的微阻抗生物传感器与不同的拓扑结构。
Microimpedance affinity biosensors using interdigitated electrodes are being extensively employed for label free and rapid detection of bacteria molecules. To improve the sensitivity of such sensors, it is required to maximize the antibody immobilization and bacteria captured for an applied input concentration through proper quantification and also optimize the electrode geometry to achieve maximum signal to noise ratio. In this paper, a biomolecule compatible electrical model has been developed which quantifies the number of immobilized antibody and captured bacteria by simple calculations from impedance spectroscopy results which are comparable to the accuracy obtained by conventional time consuming and sometimes expensive biochemical methods and can also estimate the electrode impedance associated with each biomolecule. The model has been applied for the detection of Escherichia coli K12 bacteria by antibody–antigen binding method on gold electrodes with PBS as the background solution. The quantitative estimation of the actual number of antibody immobilized and bacteria captured for input concentration of 103and 106CFU/ml on the gold surface in this case has been matched with the conventional optical density methods and radioactive labeling method respectively. A quantitative relationship between the geometrical parameters and the output signal has been deduced after extracting the electrode impedance for each biomolecule and the effects of transducer geometry on the sensitivity of this biosensor have been matched with recently reported experimental results for the same system. Thus the proposed model enables quantitative estimation of the antibody immobilized and bacteria captured and quantitative prediction of the optimum geometry for maximum sensitivity eliminating the need for trial and error experimentation. This will lead to a rapid and cost effective method for performance enhancement of microimpedance biosensors with different topologies.