Li Fang, Luo Mingming, Tan Yijun, Liu Ruowei, Xu Longping, Zhao Pei, Wu Zijian
School of Information Engineering, Tianjin University of Commerce, Tianjin, China.
Tianjin Key Laboratory of Food Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, No. 409, Guangrong Road, Tianjin, China.
Mikrochim Acta. 2025 Jul 25;192(8):519. doi: 10.1007/s00604-025-07393-6.
A dual-mode electrochemical and fluorescent sensing platform for the highly sensitive detection of kanamycin (KANA) in milk was constructed, which leveraged the synergistic effects of carbon dots (CDs)-loaded metal-organic frameworks (CDs@Cu/Al-MOF) and TiC, along with the competitive binding of complementary DNA (cDNA) strands to KANA-specific aptamers. Loading CDs onto Cu/Al-MOF effectively prevented the aggregation of CDs and shielded the fluorescent signals from environmental interference, significantly enhancing signal stability. When a glassy carbon electrode (GCE) functionalized with TiC and aptamers was immersed in a solution of cDNA-functionalized CDs@Cu/Al-MOF, the aptamers hybridized with the cDNA, anchoring the CDs@Cu/Al-MOF onto the GCE surface. This resulted in enhanced electrochemical signals and weakened fluorescence intensity in the solution. Upon introduction of KANA, the aptamer preferentially bound to KANA and the cDNA/CDs@Cu/Al-MOF detached from the electrode, leading to a decrease in the electrochemical signal and an increase in the fluorescence signal. The developed dual-mode aptasensor enabled highly sensitive detection of KANA within a range of 100 fM-1 μM, with the limit of detection (LOD) as low as 0.5254 fM (electrochemical mode) and 0.4398 fM (fluorescence mode). The dual-mode aptasensor exhibited excellent selectivity, reproducibility, and promising performance in real milk sample analysis.
构建了一种用于高灵敏检测牛奶中卡那霉素（KANA）的双模式电化学和荧光传感平台，该平台利用了负载碳点（CDs）的金属有机框架（CDs@Cu/Al-MOF）与TiC的协同效应，以及互补DNA（cDNA）链与KANA特异性适配体的竞争性结合。将CDs负载到Cu/Al-MOF上有效地防止了CDs的聚集，并屏蔽了荧光信号免受环境干扰，显著增强了信号稳定性。当用TiC和适配体功能化的玻碳电极（GCE）浸入cDNA功能化的CDs@Cu/Al-MOF溶液中时，适配体与cDNA杂交，将CDs@Cu/Al-MOF锚定在GCE表面。这导致溶液中的电化学信号增强，荧光强度减弱。引入KANA后，适配体优先与KANA结合，cDNA/CDs@Cu/Al-MOF从电极上脱离，导致电化学信号降低，荧光信号增加。所开发的双模式适配体传感器能够在100 fM - 1 μM范围内高灵敏检测KANA，检测限（LOD）低至0.5254 fM（电化学模式）和0.4398 fM（荧光模式）。该双模式适配体传感器在实际牛奶样品分析中表现出优异的选择性、重现性和良好的性能。
