Nano Electronic Center of Excellence, Thin Film and Nanoelectronic Lab, School of Electrical and Computer Engineering, University of Tehran, P.O. Box 14395/515, Tehran, Iran.
Nano Electronic Center of Excellence, Thin Film and Nanoelectronic Lab, School of Electrical and Computer Engineering, University of Tehran, P.O. Box 14395/515, Tehran, Iran.
Biosens Bioelectron. 2014 Sep 15;59:151-9. doi: 10.1016/j.bios.2014.02.079. Epub 2014 Mar 15.
Detection of rare metastatic cells within a benign tumor is a key challenge to diagnose the cancerous stage of the patients tested by clinical human biopsy or pap smear samples. We have fabricated and tested a nanograssed silicon based bioelectronic device with the ability of detecting a few human colon invasive cancer cells (SW48) in a mixed cell culture of primary cancerous colon cells (HT29) without any biochemical labels. A discernible impedance change was elicited after the presence of 5% metastatic cells in the whole benign sample. The electric field penetration as well as current flow to metastatic cells is different from benign ones due to their different membrane dielectric parameters. Beta dispersion as one of intrinsic bioelectrical properties of the cell membrane in blocking the stimulating current flow in the range of kHz is the specific parameter involved in our diagnosis approach. It can reflect in-depth information about the dielectric properties and the pathological condition of a cell before and after metastatic transformation. Electrically active doped silicon nanograss structures owing to their superior nanocontacts with cell membrane can detect any slight variations in current being originated from the presence of rare metastatic cells on the surface of the sensing electrode. The experimental results revealed that bare doped silicon microelectrodes are incapable of resolving different grades of attached cells.
在临床人体活检或巴氏涂片样本中检测到的良性肿瘤内检测罕见的转移性细胞，是诊断癌症阶段患者的关键挑战。我们已经制造并测试了一种基于纳米草硅的生物电子设备，该设备能够在没有任何生化标记物的情况下，检测混合培养的原代结肠癌细胞（HT29）中的少量人结肠侵袭性癌细胞（SW48）。在整个良性样本中存在 5%的转移性细胞后，会引起可识别的阻抗变化。由于它们的膜介电参数不同，转移性细胞和良性细胞的电场穿透和电流流动方式不同。β分散是细胞膜内在生物电特性之一，它可以阻止刺激电流在 kHz 范围内流动，是我们诊断方法中涉及的特定参数。它可以反映出细胞膜介电特性和转移性前、后的病理状态的深入信息。由于具有与细胞膜的优越纳米接触，掺杂物硅纳米草结构可以检测到源于传感电极表面上罕见转移性细胞的任何微小电流变化。实验结果表明，裸露的掺杂硅微电极无法分辨不同等级的附着细胞。
