Effect of electrode configuration on the sensitivity of nucleic acid detection in a non-planar, flow-through, porous interdigitated electrode
Effect of electrode configuration on the sensitivity of nucleic acid detection in a non-planar, flow-through, porous interdigitated electrode
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DOI：
10.1063/1.5126452
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发表时间：
2019-11-01
期刊：
影响因子：
3.2
通讯作者：
Basuray, Sagnik
中科院分区：
文献类型：
--
作者：
Cheng, Yu-Hsuan;Moura, Pedro Antonio Reis;Basuray, Sagnik
电阻抗光谱（EIS）传感器虽然快速、经济，但往往存在灵敏度差的问题。用碳基换能器修饰的EIS传感器显示出更高的电导，从而增加了传感器对生物分子（如DNA）的灵敏度。然而，EIS光谱受到双电层（EDL）寄生电容的影响。在这里，一种新的剪切增强，流过无孔，非平面交错微电极传感器已经被制造，将EDL电容器转移到高频。该传感器中增强的对流输运破坏了EDL的扩散动力学，将其EIS光谱移至高频。同时，DNA检测信号向高频偏移，使传感器具有较高的信噪比，灵敏度高，速度快。该装置由夹在上下两组交错微电极之间的微流控通道组成。其中一组微电极被碳基换能器材料填充，如羧化单壁碳纳米管（SWCNT）。对传感器的三种不同电极配置以及不同碳基换能器材料进行了多参数研究，以了解基本的物理和电化学。装有swcnts的传感器对短目标dna的所有不同电极配置都显示出飞摩尔检测灵敏度。与其他电极配置相比，从独特的工作电极配置中可以注意到信号的20倍跳跃。这证明了传感器在DNA和其他生物分子的检测灵敏度方面有显著提高的潜力。由AIP出版社授权出版。
Electrical impedance spectroscopy (EIS) sensors, though rapid and cost-effective, often suffer from poor sensitivity. EIS sensors modified with carbon-based transducers show a higher conductance, thereby increasing the sensitivity of the sensor toward biomolecules such as DNA. However, the EIS spectra are compromised by the parasitic capacitance of the electric double layer (EDL). Here, a new shear-enhanced, flow-through nonporous, nonplanar interdigitated microelectrode sensor has been fabricated that shifts the EDL capacitor to high frequencies. Enhanced convective transport in this sensor disrupts the diffusion dynamics of the EDL, shifting its EIS spectra to high frequency. Concomitantly, the DNA detection signal shifts to high frequency, making the sensor very sensitive and rapid with a high signal to noise ratio. The device consists of a microfluidic channel sandwiched between two sets of top and bottom interdigitated microelectrodes. One of the sets of microelectrodes is packed with carbon-based transducer material such as carboxylated single-walled carbon nanotube (SWCNT). Multiple parametric studies of three different electrode configurations of the sensor along with different carbon-based transducer materials are undertaken to understand the fundamental physics and electrochemistry. Sensors packed with SWCNT show femtomolar detection sensitivity from all the different electrode configurations for a short target-DNA. A 20-fold jump in the signal is noticed from the unique working electrode configuration in contrast to the other electrode configurations. This demonstrates the potential of the sensor to have a significant increase in detection sensitivity for DNA and other biomolecules. Published under license by AIP Publishing.