Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710119, China.
Anal Methods. 2024 Oct 3;16(38):6538-6545. doi: 10.1039/d4ay01044b.
A colorimetric aptasensor based on the dual recognition of magnetic carbon dots (M-CDs) and copper-based metal-organic frameworks (Cu-MOFs) was constructed for the visual detection of (). Aptamer-modified Cu-MOFs could specifically identify target bacteria and exhibited peroxidase-like activity by catalyzing the colorimetric reaction of the 3,3',5,5'-tetramethylbenzidine-HO (TMB-HO) system. M-CDs electrostatically attracted bacteria because of their strong positive electrical properties and offered better capturing performance compared with magnetic beads owing to their smaller size. Visual detection of the target was achieved using the color change of the reaction catalyzed by the resuspension of the sandwich-structured complex. The bacteria were sensitively detected with a limit of detection (LOD) of 1 CFU mL using the peroxidase catalytic activity of Cu-MOFs. Non-target bacteria produced negative results, demonstrating the excellent selectivity of the proposed aptasensor. The strategy showed good recovery in real sample detection, showing great potential for visual monitoring of pathogenic bacteria, and could provide a reference for further development of novel sensing platforms for bacterial detection.
基于磁性碳点 (M-CDs) 和基于铜的金属有机骨架 (Cu-MOFs) 的双重识别，构建了用于检测 () 的比色适体传感器。适配体修饰的 Cu-MOFs 可以特异性识别靶细菌，并通过催化 3,3',5,5'-四甲基联苯胺-HO (TMB-HO) 体系的比色反应表现出过氧化物酶样活性。由于其较强的正电性，M-CDs 静电吸引细菌，并且由于其较小的尺寸，与磁性珠相比，提供了更好的捕获性能。通过重新悬浮夹心结构复合物所催化的反应的颜色变化来实现对目标的可视化检测。由于 Cu-MOFs 的过氧化物酶催化活性，该细菌被灵敏地检测到，检测限 (LOD) 为 1 CFU mL。非靶细菌产生阴性结果，表明该适体传感器具有优异的选择性。该策略在实际样品检测中表现出良好的回收率，为病原微生物的可视化监测提供了巨大潜力，并可为细菌检测的新型传感平台的进一步发展提供参考。
