Abstract：
Herein, a new dual-model photoelectrochemical (PEC)/electrochemical (EC) sensor based on Z-scheme titanium dioxide (TiO2) disk/methylene blue (MB) sensibilization for the detection of kanamycin (Kana) was developed. Metal-organic framework-derived porous TiO2 disks were synthesized and exhibited excellent anodic photocurrent under visible light excitation. Subsequently, amino-labeled double-stranded DNA (dsDNA) was introduced into the modified electrode. Photocurrent was enhanced with MB embedded in dsDNA to form Z-scheme TiO2/MB sensibilization. When the target, Kana, was present, it specifically bound to the aptamer in the dsDNA, leading to the disruption of the dsDNA structure and the release of MB. This release of MB and the increase in target spatial resistance resulted in a significant weakening of PEC signal and a decreased oxidation peak current of MB. The PEC sensor successfully detected Kana in the range of 2-1000 pM with an LOD of 0.17 pM. Meanwhile, the EC sensor for Kana detection showed a linear range of 5-500 pM with an LOD of 1.8 pM. Additionally, the sensor exhibited excellent selectivity, reproducibility, stability, and good recoveries when applied to milk and honey samples. As a result, this method has the potential for application in ensuring food safety through the rapid determination of antibiotics in food.
摘要：
在这里，开发了一种基于Z方案二氧化钛（TiO2）圆盘/亚甲基蓝（MB）敏化的新型双模光电化学（PEC）/电化学（EC）传感器，用于检测卡那霉素（Kana）。合成了金属有机骨架衍生的多孔TiO2圆盘，并在可见光激发下表现出优异的阳极光电流。随后，将氨基标记的双链DNA(dsDNA)引入修饰电极中。用嵌入dsDNA中的MB增强光电流以形成Z-方案TiO2/MB敏化。当目标,Kana,在场,它与dsDNA中的适体特异性结合，导致dsDNA结构的破坏和MB的释放。MB的释放和目标空间电阻的增加导致PEC信号的显着减弱和MB的氧化峰电流的降低。PEC传感器成功检测到2-1000pM范围内的假名，LOD为0.17pM。同时,用于假名检测的EC传感器显示5-500pM的线性范围，LOD为1.8pM。此外,该传感器表现出优异的选择性，再现性，稳定性,和良好的回收率，当应用于牛奶和蜂蜜样品。因此,该方法通过快速测定食品中的抗生素，在保证食品安全方面具有潜在的应用价值。
