College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
Biosens Bioelectron. 2014 May 15;55:195-202. doi: 10.1016/j.bios.2013.11.061. Epub 2013 Dec 7.
A novel 2-dimensional graphene analog molybdenum disulfide/multi-walled carbon nanotube (MoS2/MWCNT) was synthesized by a simple hydrothermal method to achieve excellent electrochemical properties. An ultrasensitive electrochemical DNA biosensor was subsequently constructed by assembling a thiol-tagged DNA probe on a MoS2/MWCNT and gold nanoparticle (AuNP)-modified electrode that has already been coupled with glucose oxidase (GOD). In this work, GOD was used as a redox marker. The heteronanostructure formed on the biosensor surface appeared relatively good conductor for accelerating the electron transfer, while the modification of GOD and AuNPs provided multiple signal amplification for electrochemical biosensing. The multiple signal amplification strategy produced an ultrasensitive electrochemical detection of DNA down to 0.79 fM with a linear range from 10 fM to 10(7)fM, and appeared high selectivity to differentiate three-base mismatched DNA and one-base mismatched DNA. The developed approach provided a simple and reliable method for DNA detection with high sensitivity and specificity, and would open new opportunities for sensitive detection of other biorecognition events.
一种新型二维石墨烯类似物二硫化钼/多壁碳纳米管（MoS2/MWCNT）通过简单的水热法合成，以实现优异的电化学性能。随后，通过将巯基标记的 DNA 探针组装到 MoS2/MWCNT 和金纳米粒子（AuNP）修饰的电极上，构建了一种超灵敏的电化学 DNA 生物传感器，该电极已经与葡萄糖氧化酶（GOD）偶联。在这项工作中，GOD 被用作氧化还原标记物。在生物传感器表面形成的杂纳米结构表现出相对较好的导电性，可加速电子转移，而 GOD 和 AuNPs 的修饰则为电化学生物传感提供了多种信号放大。该多重信号放大策略实现了对 DNA 的超灵敏电化学检测，检测下限低至 0.79 fM，线性范围为 10 fM 至 10(7)fM，并且对三碱基错配 DNA 和单碱基错配 DNA 具有高选择性。所开发的方法为具有高灵敏度和特异性的 DNA 检测提供了一种简单可靠的方法，并将为其他生物识别事件的灵敏检测开辟新的机会。
