基于三维磁性纳米材料基底和生物滚动放大技术的适配子法多元化电化学传感器的研究

Based on our current research of the multiple electrochemical aptasensor applied by gold nanoparticles, in this work, in order to further improve the sensitivity of the aptasensor, two methods are involved. On the one hand, the magnetic nanorod @ gold nanoparticles with the core-shell structure are used as the interface of the elecctrochemical sensor, and aptamers are used as the detection probes. With the 3-D flexible electrode surface under the magnetic field, more probes could be attached, leading to the higher sensitivity. On the other hand, the rolling circle amplification (RCA) is also applied , the binding of more target molecules results in the longer primer strand, leading to the more and more signals absorbed onto the products of RCA. Due to this dual amplification method, the sensitivity of the aptasensor could be greatly improved, and a few numbers of target molecules are expected to be detected. Additionally, the multiple redox tags are also induced in this design, which make it possible that we can carry out the multiple analysis at the same time, then the efficiency of sensor will be greatly enhanced. If the design and the application of this proposed senosr are successful, the concentration of the targets with fM or even lower could be detected, so that the early prevention for cancer or other serious diseases could be performed.

本项目是基于目前的关于利用纳米金颗粒固定生物适配子法多元化电化学传感器的研究基础，为了进一步提高传感器的灵敏度，作了两方面的改进。一方面改进是采用核-壳结构的外层包裹纳米金颗粒的磁性纳米棒作为传感基底，适配子作传感探针。由于基底的三维空间化，在磁场调节下，灵活可控，能够更多地吸附传感探针，有效地提高了灵敏性。另一方面是采用生物的滚动放大技术，由于目标分子的结合，使引物链不断增长，从而进一步增多吸附的信号标记分子，使信号进一步地放大。由于采用这种双重放大技术，使传感器的灵敏度得到进一步地提高，有望达到分子水平数量级的检测。另外，该传感器设计中引入了多元化电化学氧化还原标记，使之能够简单灵敏地实现一次性多种目标分子的检测，极大地提高传感效率。如果该电化学适配子生物传感器能够成功的设计与应用，有望检测fM甚至更低浓度量级的目标分子，为癌症以及其它一些严重疾病做出提前诊断和预防。

本项目是以纳米金颗粒固定生物适配子法的电化学传感器为主要的研究内容，为了进一步提高传感器的灵敏度，一方面是传感基底的改进，合成出各种形貌的，具有高能面和高的比表面积的纳米金颗粒，这样具有特殊形貌的纳米金颗粒可以极大地提高适配子的修饰数量，从而达到提高灵敏度的目的。另一方面，采用生物的滚动放大技术，由于目标分子的结合，使引物链不断增长，从而进一步增多吸附的信号标记分子，使信号进一步地放大。由于采用这种双重放大技术，使传感器的灵敏度得到进一步地提高，可以达到分子水平数量级的检测。通过不断的实验研究，我们目前已经可以检测实际生物样品，用于癌症标记物、环境污染物等高灵敏度检测。