A highly sensitive sensor for Cu2+ with unmodified gold nanoparticles and DNAzyme by using the dynamic light scattering technique
A highly sensitive sensor for Cu2+ with unmodified gold nanoparticles and DNAzyme by using the dynamic light scattering technique
复制标题
利用动态光散射技术，使用未修饰的金纳米粒子和 DNAzyme 构建高灵敏度 Cu2 传感器
DOI：
10.1039/c2an35217f
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发表时间：
2012-01-01
期刊：
影响因子：
4.2
通讯作者：
Shuai, Xintao
中科院分区：
文献类型：
--
作者：
Miao, Xiangmin;Ling, Liansheng;Shuai, Xintao
铜离子（Cu2+）在许多生物反应中发挥着重要作用，适当水平的Cu2+是生命正常代谢所必需的。因此，开发一种灵敏且简单的方法来测定 Cu2+ 至关重要。在这里，基于使用动态光散射（DLS）检测AuNPs的平均流体动力学直径，开发了一种新颖且灵敏的Cu2+传感器。 Cu2+特异性DNAzyme是双链的，不能吸附在AuNPs的表面，因此加入NaCl会发生AuNPs的聚集。然而，Cu2+可以裂解DNAzyme并释放单链DNA（ssDNA）片段，该片段可以吸附在AuNPs的表面并阻止它们聚集。添加Cu2+前后AuNPs上DNA吸附能力的差异直接影响AuNPs的分散状态，进而影响其平均流体动力学直径，可以通过DLS技术检测到。基于上述原理，可实现100 pM至2.0 nM范围内的Cu2+检测，线性回归方程为D = 306.73 - 89.66C（C：nM，R = 0.9953），检测限为60 pM（3 delta/斜率）。此外，将该方法应用于水样中Cu2+的检测，得到了满意的结果。
Copper ion (Cu2+) plays an important role in many biological reactions, and a suitable level of Cu2+ is necessary for the regular metabolism of life. Thus developing a sensitive and simple method for determination of Cu2+ is essential. Here, a novel and sensitive Cu2+ sensor was developed based on detecting the average hydrodynamic diameter of AuNPs by using dynamic light scattering (DLS). Cu2+-specific DNAzyme was double-strand and could not adsorb on the surface of AuNPs, accordingly AuNPs aggregation would occur with the addition of NaCl. However, Cu2+ could cleave DNAzyme and release single-stranded DNA (ssDNA) fragments, which could adsorb on the surface of AuNPs and prevent them from aggregation. Such differences in DNA adsorption ability on AuNPs before and after the addition of Cu2+ affected the disperse state of AuNPs directly, and then affected their average hydrodynamic diameter, which could be detected with the DLS technique. Based upon the above mentioned principle, detection of Cu2+ could be realized over the range from 100 pM to 2.0 nM, with a linear regression equation of D = 306.73 - 89.66C (C: nM, R = 0.9953) and a detection limit of 60 pM (3 delta/slope). Moreover, satisfactory results were obtained when the assay was applied in the detection of Cu2+ in water samples.