Nano-Electronics and Thin Film Laboratory, School of Electrical and Computer Engineering, University of Tehran, Tehran, Iran.
Lab Chip. 2012 Mar 21;12(6):1183-90. doi: 10.1039/c2lc21028b. Epub 2012 Jan 31.
A novel vertically aligned carbon nanotube based electrical cell impedance sensing biosensor (CNT-ECIS) was demonstrated for the first time as a more rapid, sensitive and specific device for the detection of cancer cells. This biosensor is based on the fast entrapment of cancer cells on vertically aligned carbon nanotube arrays and leads to mechanical and electrical interactions between CNT tips and entrapped cell membranes, changing the impedance of the biosensor. CNT-ECIS was fabricated through a photolithography process on Ni/SiO(2)/Si layers. Carbon nanotube arrays have been grown on 9 nm thick patterned Ni microelectrodes by DC-PECVD. SW48 colon cancer cells were passed over the surface of CNT covered electrodes to be specifically entrapped on elastic nanotube beams. CNT arrays act as both adhesive and conductive agents and impedance changes occurred as fast as 30 s (for whole entrapment and signaling processes). CNT-ECIS detected the cancer cells with the concentration as low as 4000 cells cm(-2) on its surface and a sensitivity of 1.7 × 10(-3)Ω cm(2). Time and cell efficiency factor (TEF and CEF) parameters were defined which describe the sensor's rapidness and resolution, respectively. TEF and CEF of CNT-ECIS were much higher than other cell based electrical biosensors which are compared in this paper.
首次展示了一种基于新型垂直排列碳纳米管的细胞阻抗传感生物传感器 (CNT-ECIS)，作为一种更快速、更灵敏和更特异的癌细胞检测设备。该生物传感器基于癌细胞在垂直排列的碳纳米管阵列上的快速捕获，导致 CNT 尖端和捕获的细胞膜之间的机械和电气相互作用，从而改变生物传感器的阻抗。CNT-ECIS 通过 Ni/SiO(2)/Si 层上的光刻工艺制造。通过直流等离子体化学气相沉积 (PECVD) 在 9nm 厚的图案化 Ni 微电极上生长碳纳米管阵列。SW48 结肠癌细胞在 CNT 覆盖的电极表面上通过，以特异性地捕获在弹性纳米管梁上。CNT 阵列既充当粘着剂又充当导电剂，阻抗变化发生得非常快，只需 30 秒（用于整个捕获和信号传递过程）。CNT-ECIS 能够检测到表面浓度低至 4000 个细胞/cm(2) 的癌细胞，灵敏度为 1.7×10(-3)Ω cm(2)。定义了时间和细胞效率因子 (TEF 和 CEF) 参数，分别描述传感器的快速性和分辨率。与本文中比较的其他基于细胞的电生物传感器相比，CNT-ECIS 的 TEF 和 CEF 要高得多。
