Laboratory of Physical Biology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China.
Anal Chem. 2011 Oct 1;83(19):7418-23. doi: 10.1021/ac201491p. Epub 2011 Aug 29.
The sensitivity of aptamer-based electrochemical sensors is often limited by restricted target accessibility and surface-induced perturbation of the aptamer structure, which arise from imperfect packing of probes on the heterogeneous and locally crowded surface. In this study, we have developed an ultrasensitive and highly selective electrochemical aptamer-based cocaine sensor (EACS), based on a DNA nanotechnology-based sensing platform. We have found that the electrode surface decorated with an aptamer probe-pendant tetrahedral DNA nanostructure greatly facilitates cocaine-induced fusion of the split anticocaine aptamer. This novel design leads to a sensitive cocaine sensor with a remarkably low detection limit of 33 nM. It is also important that the tetrahedra-decorated surface is protein-resistant, which not only suits the enzyme-based signal amplification scheme employed in this work, but ensures high selectivity of this sensor when deployed in sera or other adulterated samples.
基于适配体的电化学传感器的灵敏度通常受到限制，因为目标物的可及性受限，以及适配体结构的表面诱导扰动，这是由探针在非均相和局部拥挤表面上的不完全组装引起的。在这项研究中，我们基于 DNA 纳米技术传感平台开发了一种超灵敏和高选择性的基于适配体的可卡因电化学传感器 (EACS)。我们发现，电极表面修饰有适配体探针-悬挂四面体 DNA 纳米结构，极大地促进了可卡因诱导的分裂可卡因适配体的融合。这种新颖的设计导致了一种灵敏的可卡因传感器，其检测限低至 33 nM。同样重要的是，四面体修饰的表面具有抗蛋白性，这不仅适合于本工作中采用的基于酶的信号放大方案，而且确保了该传感器在血清或其他掺杂样品中具有高选择性。
