Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Safety Assessment of Genetically Modified Organism (Food Safety), Ministry of Agriculture, P.R. China, Beijing 100083, China; Beijing laboratory for food quality and safety, college of food science and nutritional engineering, china agricultural university, Beijing 100083, China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Safety Assessment of Genetically Modified Organism (Food Safety), Ministry of Agriculture, P.R. China, Beijing 100083, China.
Biosens Bioelectron. 2018 Nov 30;120:168-174. doi: 10.1016/j.bios.2018.08.033. Epub 2018 Aug 16.
An electrochemical biosensor based on Cu-dependent cleavage DNAzyme (cDNAzyme), Exponential Amplification Reaction (EXPAR), and single-strand triggered DNA hybridization chain reaction (HCR) was developed for detecting the copper (II) ions. This method capitalizes on the specific recognition of cDNAzyme, the single strand accumulated isothermal amplification of EXPAR, and the enzyme-free isothermal DNA assembly of HCR. In the presence of Cu, the catalytic chain of cDNAzyme split the substrate chain to produce single-stranded DNA (Oligo X). With the help of the EXPAR, the trace Oligo X was amplified and converted to the initiator DNA (Oligo Y). After adding the initiator DNA (Oligo Y) into nanochannel, massive DNA superstructures grew from the capture probe (CP) that were pre-immobilized on the nanochannel wall, resulting in a sharp decrease of the effective diameter of the nanochannel. As a result, the transmembrane ionic current significantly decreased due to the effective closing of the nanochannel. Finally, the copper (II) ion was detected by monitoring the changes of transmembrane ionic current. The developed electrochemical biosensor also displayed high selectivity for Cu, which could be useful for monitoring Cu above ten picomole.
基于铜依赖性切割 DNA 酶 (cDNAzyme)、指数扩增反应 (EXPAR) 和单链触发 DNA 杂交链式反应 (HCR) 的电化学生物传感器被开发用于检测铜 (II) 离子。该方法利用了 cDNAzyme 的特异性识别、EXPAR 的单链等温扩增和无酶等温 DNA 组装的 HCR。在 Cu 的存在下，cDNAzyme 的催化链将底物链分裂，产生单链 DNA (Oligo X)。在 EXPAR 的帮助下，痕量的 Oligo X 被扩增并转化为起始 DNA (Oligo Y)。在将起始 DNA (Oligo Y) 添加到纳米通道后，大量的 DNA 超结构从预先固定在纳米通道壁上的捕获探针 (CP) 上生长，导致纳米通道的有效直径急剧减小。结果，由于纳米通道的有效闭合，跨膜离子电流显著降低。最后，通过监测跨膜离子电流的变化来检测铜 (II) 离子。所开发的电化学生物传感器对 Cu 具有高选择性，可用于监测超过十皮摩尔的 Cu。
