School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, Shandong Province, China.
School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 12 Zhangzhou Road, Zibo 255049, Shandong Province, China; Shandong Provincial Engineering Research Center of Vegetable Safety and Quality Traceability, No. 12 Zhangzhou Road, Zibo 255049, Shandong Province, China.
Sci Total Environ. 2022 Sep 15;839:156276. doi: 10.1016/j.scitotenv.2022.156276. Epub 2022 May 27.
A dual-model colorimetric and electrochemical aptasensor was designed using a large number of G-quadruplexes generated by rolling circle amplification (RCA). Specific binding between target and aptamer during RCA yielded large numbers of G-quadruplexes. A colorimetric sensor was fabricated based on the interaction between the G-quadruplex and hemin, which altered the 3,3',5,5'-Tetramethylbenzidine (TMB)-catalyzed color reaction and facilitated the visual and semi-quantitative detection of kanamycin. An electrochemical sensor was constructed based on the strong interaction between the G-quadruplex and the methylene blue electrical signal molecule. Combining nanocomposites multi-walled carbon nanotubes-chitosan/gold nanoparticles (MWCNTs-CS/AuNPs) and RCA realized double-amplified electrochemical signals. Under optimized conditions, a linear relationship was obtained as the logarithm of different concentrations of kanamycin (KAN). The colorimetric aptasensor had a linear range of 1 × 10 nM to 1 × 10 nM with a detection limit of 1.949 nM. The electrochemical aptasensor had wider a linear range from 1 × 10 nM to 2.5 × 10 nM and a lower detection limit of 0.333 pM. The sensor combined the advantages of simple colorimetric visualization with the ultra-precision of electrochemical methods. Aptasensor showed good specificity and prevented interference. Furthermore, the prepared dual-model aptasensor facilitated the practical monitoring of KAN in milk.
设计了一种基于滚环扩增（RCA）产生的大量 G-四链体的双模式比色和电化学生物传感器。在 RCA 过程中，靶标与适体之间的特异性结合产生了大量的 G-四链体。基于 G-四链体与辣根过氧化物酶之间的相互作用，制备了比色传感器，该传感器改变了 3,3',5,5'-四甲基联苯胺（TMB）催化的显色反应，促进了卡那霉素的可视化和半定量检测。基于 G-四链体与亚甲基蓝电信号分子之间的强相互作用，构建了电化学生物传感器。结合纳米复合材料多壁碳纳米管-壳聚糖/金纳米粒子（MWCNTs-CS/AuNPs）和 RCA 实现了电化学信号的双重放大。在优化条件下，得到了不同浓度卡那霉素（KAN）对数与电化学信号之间的线性关系。比色生物传感器的线性范围为 1×10⁻⁹ nM 至 1×10⁻⁶ nM，检测限为 1.949 nM。电化学生物传感器的线性范围更宽，从 1×10⁻⁹ nM 至 2.5×10⁻⁶ nM，检测限为 0.333 pM。该传感器结合了比色可视化的简单优势和电化学方法的超高精度。适体传感器表现出良好的特异性，可防止干扰。此外，制备的双模式适体传感器有助于实际监测牛奶中的 KAN。
