Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
Mikrochim Acta. 2018 Feb 5;185(3):156. doi: 10.1007/s00604-018-2694-9.
An electrochemical biosensor for the detection of microRNA was prepared via chemical grafting of a Methylene Blue labeled reporter (MB-Rep) duplex onto a nanostructured surface that was obtained by electrodeposition of cobalt oxide and poly(o-phenylenediamine). This is followed by the attachment of hyaluronic acid and gold nanoclusters. In the presence of the target (microRNA), the probe-target duplex and the MB-Rep hairpin are formed. These will displace the labeled reporter from the sensor surface, and this results in a decrease of the amperometric signal for MB at a typical working voltage of -0.28 V (vs. Ag/AgCl). The electrode modified with hyaluronic acid possesses a large electroactive surface area and an excellent antifouling property. This makes it useful for ultrasensitive quantitation of microRNA even in complex biological media. The sensor has a linear response in the 100 f. to 0.1 μM microRNA concentration range, and a 33.3 f. detection limit. It was successfully applied to the determination of microRNA in cancer cells. Graphical abstract ᅟ.
一种电化学生物传感器，用于检测 microRNA，是通过将亚甲基蓝标记的报告分子（MB-Rep）双链体化学接枝到纳米结构表面上而制备的，该纳米结构表面是通过氧化钴和聚邻苯二胺的电沉积获得的。随后，将透明质酸和金纳米簇附着在上面。在存在靶标（microRNA）的情况下，形成探针-靶标双链体和 MB-Rep 发夹。这些会将标记的报告分子从传感器表面置换出来，这导致在典型工作电压为-0.28 V（相对于 Ag/AgCl）时，MB 的电流信号降低。用透明质酸修饰的电极具有较大的电活性表面积和出色的抗污性能。这使其即使在复杂的生物介质中也可用于超灵敏定量 microRNA。该传感器在 100 fM 至 0.1 μM microRNA 浓度范围内具有线性响应，检测限为 33.3 fM。它已成功用于癌细胞中 microRNA 的测定。
