Shear and AC Field Enhanced Carbon Nanotube Impedance Assay for Rapid, Sensitive, and Mismatch-Discriminating DNA Hybridization
Shear and AC Field Enhanced Carbon Nanotube Impedance Assay for Rapid, Sensitive, and Mismatch-Discriminating DNA Hybridization
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DOI：
10.1021/nn9004632
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发表时间：
2009-07-01
期刊：
影响因子：
17.1
通讯作者：
Chang, Hsueh-Chia
中科院分区：
文献类型：
--
作者：
Basuray, Sagnik;Senapati, Satyajyoti;Chang, Hsueh-Chia
除了将目标分子集中在传感器位置之外，我们还展示了在高频AC电场存在下用于碳纳米管（CNT）表面上的DNA杂交的开流阻抗传感平台的两个明显的新优点。剪切增强的DNA和离子传输速率的CNT表面的寄生双层交流阻抗信号的电荷转移信号，由于DNA杂交。高AC频率下的流场还放大了穿过杂交CNT的电荷转移速率，并在来自靶向物种的DNA与在靶向附着区域中的26个碱基中具有三个核苷酸错配的密切相关的同源物种之间提供剪切增强的区分。这允许在基于无标记CNT的微流体检测平台中，在小于20分钟内用皮摩尔靶DNA浓度灵敏地检测杂交事件。
Other than concentrating the target molecules at the sensor location, we demonstrate two distinct new advantages of an open-flow impedance-sensing platform for DNA hybridization on carbon nanotube (CNT) surface in the presence of a high-frequency AC electric field. The shear-enhanced DNA and ion transport rate to the CNT surface decouples the parasitic double-layer AC impedance signal from the charge-transfer signal due to DNA hybridization. The flow field at high AC frequency also amplifies the charge-transfer rate across the hybridized CNT and provides shear-enhanced discrimination between DNA from targeted species and a closely related congeneric species with three nucleotide mismatches out of 26 bases in a targeted attachment region. This allows sensitive detection of hybridization events in less than 20 min with picomolar target DNA concentrations in a label-free CNT-based microfluidic detection platform.