Quantitative detection of single walled carbon nanotube in water using DNA and magnetic fluorescent spheres.
Quantitative detection of single walled carbon nanotube in water using DNA and magnetic fluorescent spheres.
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DOI：
10.1021/es303671u
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发表时间：
2013-01
影响因子：
11.4
通讯作者：
L. C. Mota;E. Ureña-Benavides;Y. Yoon;A. Son
中科院分区：
文献类型：
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作者：
L. C. Mota;E. Ureña-Benavides;Y. Yoon;A. Son
碳纳米管（Carbon nanotubes, cnt）由于其独特的性能，在许多领域得到了广泛的研究和应用。鉴于碳纳米管不受管制地释放到环境中，对碳纳米管日益增长的需求构成了重大的公共健康风险。不幸的是，由于现有检测方法的限制，关于环境中碳纳米管的实际数量存在很大的信息缺口。这主要是由于碳纳米管无处不在的碳化学。作为回应，我们开发了一种方法（碳纳米管捕获方法），能够在水介质中从结构上区分碳纳米管与其他干扰碳材料。利用单壁纳米管（SWNTs）与特定单链DNA （ssDNA）之间的亲和力捕获水中的单壁纳米管。通过磁分离获得了swnt特异性分离。双荧光标记贴于夹心ssDNA探针进行定量。DNA和单壁碳纳米管之间的特异性亲和力被证实，没有观察到显著的侧相互作用。在优化的孵育时间（30 min）和缓冲液组成（10(-7)%十二烷基硫酸钠和pH 7.9）下，以石墨烯为平面类似物，在SWNT浓度（0.05 ~ 10 μg/mL）范围内获得定量校准曲线（R(2) = 0.90）。与其他基于光谱的方法进行了比较，以突出该方法在水生样品中碳纳米管检测的特异性和敏感性。
Carbon nanotubes (CNTs) possess unique properties that have led to an increase in their research and usage for a wide variety of fields. This growing demand of CNTs poses a major public health risk given its unregulated release into the environment. Unfortunately there is a significant information gap on the actual quantity of CNTs in the environment due to limitation of existing detection methods. This is mainly owing to the ubiquitous carbon chemistry of CNT. In response we developed a method (CNT-capture method) that is able to structurally differentiate CNT from other interference carbon materials in an aqueous medium. The affinity between single walled nanotubes (SWNTs) and specific single stranded DNA (ssDNA) was employed to capture SWNTs in water. SWNT-specific separation was obtained via magnetic separation. Dual fluorescent labels attached to sandwich ssDNA probes were used for quantification. The specific affinity between DNA and SWNTs was verified and no significant side-interactions were observed. With optimized incubation duration (30 min) and buffer composition (10(-7) % sodium dodecyl sulfate and pH 7.9), a calibration curve of quantification (R(2) = 0.90) was obtained with a range of SWNT concentration (0.05-10 μg/mL) against graphene as a planar analog. Comparison to other spectroscopy based methods was carried out to highlight the specificity and sensitivity of the presented method for CNT detection in aquatic sample.