Department of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India; Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi 110025, India.
Biosens Bioelectron. 2013 Dec 15;50:406-13. doi: 10.1016/j.bios.2013.07.006. Epub 2013 Jul 11.
Nanostructured magnesium oxide (size<10nm) grafted carboxyl (COOH) functionalized multi-walled carbon nanotubes (nMgO-cMWCNTs) deposited electrophoretically onto indium tin oxide (ITO) coated glass electrode and have been utilized for Vibrio cholerae detection. Aminated 23 bases single stranded DNA (NH2-ssDNA) probe sequence (O1 gene) of V. cholerae has been covalently functionalized onto nMgO-cMWCNTs/ITO electrode surface using EDC-NHS chemistry. This DNA functionalized MgO grafted cMWCNTs electrode has been characterized using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical techniques. The results of XPS studies reveal that sufficient O-C=O groups present at the nMgO-cMWCNTs surface are utilized for DNA binding. The results of hybridization studies conducted with fragmented target DNA (ftDNA) of V. cholerae using electrochemical impedance spectroscopy (EIS) reveal sensitivity as 3.87 Ω ng(-1) cm(-2), detection limit of ~21.70 ng µL(-1) in the linear range of 100-500 ng µL(-1) and stability of about 120 days. The proposed DNA functionalized nMgO-cMWCNTs nanomatrix provides a novel impedimetric platform for the fabrication of a compact genosensor device for biomedical application.
纳米结构氧化镁（尺寸<10nm）接枝羧基（COOH）功能化多壁碳纳米管（nMgO-cMWCNTs）通过电泳沉积在氧化铟锡（ITO）涂覆的玻璃电极上，并已用于霍乱弧菌检测。霍乱弧菌的氨化 23 个碱基单链 DNA（NH2-ssDNA）探针序列（O1 基因）已通过 EDC-NHS 化学共价功能化到 nMgO-cMWCNTs/ITO 电极表面。使用 X 射线光电子能谱（XPS）、傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和电化学技术对 DNA 功能化 MgO 接枝 cMWCNTs 电极进行了表征。XPS 研究结果表明，nMgO-cMWCNTs 表面存在足够的 O-C=O 基团可用于 DNA 结合。使用电化学阻抗谱（EIS）对霍乱弧菌的断裂靶 DNA（ftDNA）进行杂交研究的结果表明，灵敏度为 3.87 Ω ng(-1) cm(-2)，在 100-500 ng µL(-1) 的线性范围内检测限约为~21.70 ng µL(-1)，稳定性约为 120 天。所提出的 DNA 功能化 nMgO-cMWCNTs 纳米基质为生物医学应用的紧凑型基因传感器设备的制造提供了一种新颖的阻抗测定平台。
