3D nanogap interdigitated electrode array biosensors
3D nanogap interdigitated electrode array biosensors
复制标题
3D纳米间隙叉指电极阵列生物传感器
DOI：
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发表时间：
2010
影响因子：
4.3
通讯作者：
R. Solanki
中科院分区：
文献类型：
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作者：
K. Singh;A. Whited;Yaswanth Ragineni;T. Barrett;Jeff King;R. Solanki
三维叉指电极（IDE）已被研究作为生物传感器的传感元件。在这些电极附近模拟电场和电流密度作为电极宽度、间隙和高度的函数，以确定最佳几何形状。电极的高度和电极之间的差距对电极表面附近的电场和电流密度的大小和分布都有显著的影响，而电极的宽度对电场强度和电流密度的影响较小。IDE基于这些模拟制造，并通过检测C反应蛋白（CRP）来测试其性能，CRP是一种应激相关蛋白，也是炎症、心血管疾病风险指标和术后恢复的重要生物标志物。CRP特异性抗体固定在电极表面上，并监测与CRP的免疫复合物（IC）的形成。电化学阻抗谱（EIS）作为检测技术。收集在缓冲液或稀释的人血清中加标的不同浓度（1 pg/mL至10 μg/mL）的CRP的EIS数据，并拟合到等效电路模型中。发现阻力变化是对CRP浓度变化最敏感的参数。在缓冲液和5%人血清样品中，传感器响应在0.1 ng/mL至1 μg/mL范围内呈线性。使用市售的用于CRP检测的ELISA验证CRP样品。因此，在不使用标记或探针分子的情况下，确立了IDE和EIS用于检测血清生物标志物的可行性。
Three-dimensional interdigitated electrodes (IDEs) have been investigated as sensing elements for biosensors. Electric field and current density were simulated in the vicinity of these electrodes as a function of the electrode width, gap, and height to determine the optimum geometry. Both the height and the gap between the electrodes were found to have significant effect on the magnitude and distribution of the electric field and current density near the electrode surface, while the width of the electrodes was found to have a smaller effect on field strength and current density. IDEs were fabricated based on these simulations and their performance tested by detecting C-reactive protein (CRP), a stress-related protein and an important biomarker for inflammation, cardiovascular disease risk indicator, and postsurgical recuperation. CRP-specific antibodies were immobilized on the electrode surface and the formation of an immunocomplex (IC) with CRP was monitored. Electrochemical impedance spectroscopy (EIS) was employed as the detection technique. EIS data at various concentrations (1 pg/mL to 10 μg/mL) of CRP spiked in buffer or diluted human serum was collected and fitted into an equivalent electrical circuit model. Change in resistance was found to be the parameter most sensitive to change in CRP concentration. The sensor response was linear from 0.1 ng/mL to 1 μg/mL in both buffer and 5% human serum samples. The CRP samples were validated using a commercially available ELISA for CRP detection. Hence, the viability of IDEs and EIS for the detection of serum biomarkers was established without using labeled or probe molecules.