Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, Changchun, 130062, China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
Talanta. 2022 Jun 1;243:123318. doi: 10.1016/j.talanta.2022.123318. Epub 2022 Feb 15.
Based on hybridization chain reaction (HCR) and fluorescence synergism, a novel aptasensor for tobramycin was successfully constructed. Tobramycin competed with cDNA-FAM to bind aptamers immobilized on magnetic beads. After magnetic separation, the released cDNA-FAM acted as initiator to trigger HCR amplification, thus the fluorescence was significantly enhanced due to binding of SYBR Green Ⅰ (SGI) to the formed long double-stranded DNA and the synergistic fluorescence of FAM. In the absence of tobramycin, the initiator was magnetically separated and no HCR occurred, more importantly, graphene oxide can quench the fluorescence of excessive hairpins/SGI and cDNA-FAM, so almost no background signal was detected. This aptasensor can monitor tobramycin in the range of 0.3-50 μM with low detection limit of 17.37 nM. Due to the potential generality of structure-switching aptamers and effectiveness of fluorescence synergism, this enzyme-free amplification strategy can be extended to other applications by rational design of nucleic acid sequences.
基于杂交链式反应（HCR）和荧光协同作用，成功构建了一种新型的妥布霉素适体传感器。妥布霉素与荧光标记的 cDNA-FAM 竞争与固定在磁性珠上的适体结合。在磁性分离后，释放的 cDNA-FAM 充当引发剂，触发 HCR 扩增，从而由于结合到形成的长双链 DNA 上的 SYBR Green Ⅰ（SGI）和 FAM 的协同荧光，荧光显著增强。在没有妥布霉素的情况下，引发剂被磁性分离，不会发生 HCR，更重要的是，氧化石墨烯可以猝灭过量发夹/SGI 和 cDNA-FAM 的荧光，因此几乎没有检测到背景信号。该适体传感器可在 0.3-50 μM 的范围内监测妥布霉素，检测限低至 17.37 nM。由于结构切换适体的潜在通用性和荧光协同作用的有效性，通过合理设计核酸序列，这种无酶扩增策略可以扩展到其他应用。
