多指示剂标记适体探针卡那霉素传感器的电化学行为与分析性能

Electrochemical behavior and analytical performance of kanamycin biosensor based on multi-indicator modified aptamer probe

以三分子亚甲基蓝(MB)标记适体探针为分子识别元件,构建了一种卡那霉素生物传感器。该传感器采用目标物诱导探针构型变化的信号转导机制。以Au-S化学法将适体探针自组装于金电极表面形成稳定的单分子层传感界面,利用交流伏安法和循环伏安法考察了传感过程的基础电化学行为和传感器分析性能。在优化条件下,相比于单分子MB标记,该传感器的界面电活性和电流输出效率获得了明显提升。在PBS中用于目标物卡那霉素检测,检出限为3.3 nmol/L,电流响应平衡时间为15 s,同时具有高选择性、强抗污检测能力和好的平行构建稳定性。该方法检测过程免样品前处理,无需添加辅助试剂。

A kanamycin biosensor was fabricated using a DNA probe modified by 3 molecule methylene blue(MB)as the molecular recognition element.The sensor signaling mechanism was based on the change in probe conformation induced by the target binding.The 3 MB-modified aptamer probe was self-assembled on the Au electrode surface to form a stable sensing interface by Au-S chemistry.The basic electrochemical behavior and analytical performance of sensor system were investigated using alternate current voltammetry and cyclic voltammetry.Under the optimized conditions,the interfacial electroactivity and the current output efficiency were significantly improved compared with those obtained from MB-modified DNA probe.When used for the detection of target kanamycin,the sensor exhibited a low detection limit of 3.3 nmol/L and super-fast sensing speed with the current response equilibrium time of only 15 s,and showed high selectivity,strong anti-fouling ability,and good parallel fabrication stability.The method avoids sample pretreatment and does not need to add additional reagent.