Importance of Controlling Nanotube Density for Highly Sensitive and Reliable Biosensors Functional in Physiological Conditions
Importance of Controlling Nanotube Density for Highly Sensitive and Reliable Biosensors Functional in Physiological Conditions
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DOI：
10.1021/nn101198u
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发表时间：
2010-11-01
期刊：
影响因子：
17.1
通讯作者：
Zhou, Chongwu
中科院分区：
文献类型：
--
作者：
Ishikawa, Fumiaki N.;Curreli, Marco;Zhou, Chongwu
利用碳纳米管场效应晶体管的生物传感器具有巨大的潜力，可以作为下一代诊断系统的基础，而纳米管已被用于制造多种传感器。我们对密度对纳米管生物传感器性能的影响进行了系统的研究，发现该参数对于实现持续的高性能至关重要。我们发现，密度较低的纳米管器件在检测限和响应幅度方面都具有较高的灵敏度。低密度纳米管器件的检测限为1 pM an电解质缓冲液中含有高水平的电解质（离子浓度接近140mM，与血清和血浆的离子强度相匹配），进一步的研究表明，灵敏度的增强是由于纳米管网络在低密度下具有半导体性质——强栅极依赖性和较低的电容。我们使用密度优化的纳米管生物传感器检测了SARS病毒的核衣壳蛋白，并在生理条件下证明了提高的检测限。我们的研究结果表明，为了制造灵敏可靠的设备，仔细调整纳米管密度至关重要
Biosensors utilizing carbon nanotube field effect transistors have a tremendous potential to serve as the basis for the next generation of diagnostic systems While nanotubes have been employed in the fabrication of multiple sensors, little attention has previously been paid to how the nanotube density affects the biosensor performance We conducted a systematic study of the effect of density on the performance of nanotube biosensors and discovered that this parameter is crucial to achieving consistently high performance We found that devices with lower density offer higher sensitivity both in terms of detection limit and magnitude of response The low density nanotube devices resulted in a detection limit of 1 pM an electrolyte buffer containing high levels of electrolytes (ionic concentration similar to 140mM, matching the ionic strength of serum and plasma) Further investigation suggested that the enhanced sensitivity arises from the semiconductor like behavior-strong gate dependence and lower capacitance-of the nanotube network at low density Finally, we used the density optimized nanotube biosensors to detect the nucleocapsid (N) protein of the SARS virus and demonstrated improved detection limits under physiological conditions Our results show that it is critical to carefully tune the nanotube density in order to fabricate sensitive and reliable devices