石墨烯基β-内酰胺类抗生素抗性菌新型比色传感方法

In view of the abuse of β-lactam antibiotic resulted in widespread antibiotic resistance by the transformation of resistance gene, posing seriously threat to ecological safety and human health, its resistant bacteria is considered as a kind of important emerging contaminants in the environment. Therefore, it is of great significance to develop a novel sensor in realizing highly selective, highly sensitive and rapid analysis for β-lactam resistant bacteria detection. Since PBP2a is considered as the key determinant of the broad-spectrum β-lactam resistance in resistant bacteria, in combination with the excellent recognition ability of PBP2a binding aptarmer obtained by SELEX method, and the visual determination properties of graphene-Au nanoparticles complex (Gr-AuNPs), we are developing a novel unlabeled colorimetric sensor in realizing highly sensitive, highly selective and rapid analysis for β-lactam resistant bacteria detection in water environment. Its detection mechanisms is supposed as follows: the catalytic ability of Gr-AuNPs towards the reaction between peroxidase substrates and H2O2 is changed after the occurrence of specific recognization of resistance strains by the PBP2a binding aptarmer absorbed on Gr-AuNPs surface, leading to the colorimetric change in the system. The main research includes the preparation, characterization, sensing performance and recognition optimization of the graphene-based colorimetric biosensor, and further illustrating the relationship between the microscopic structure of the sensor, the preparation methods and the recognition performance. This research will provide a powerful technique in the detection of resistance strains and play an important role in guaranteeing the drinking water security.

β-内酰胺类抗生素是目前使用最广泛的抗生素，因过量使用会导致抗性基因广泛传播，严重威胁了生态环境安全和人类健康，因此其抗性菌已经成为环境中不容忽视的污染物。但是，目前尚缺少高灵敏性、高选择性和快速的检测技术。本项目提出以决定抗性菌抗药性的分子水平物质PBP2a为标志物，采用SELEX法筛选PBP2a特异性适配子，结合该适配子特异性识别能力及石墨烯-纳米金复合物(Gr-AuNPs)可视化传感性能，鉴于抗性菌与Gr-AuNPs表面的PBP2a适配子特异性结合后，改变Gr-AuNPs对过氧化氢酶底物与H2O2反应的催化活性，进而引起体系颜色的变化，实现抗性菌高灵敏、高选择性、快速检测的比色传感方法。主要研究内容包括抗性菌比色传感器的制备、表征、检测性能及识别条件优化，并通过上述研究阐明该传感器的构效关系。通过本研究为抗性菌的高灵敏性、高特异性、快速准确的定量检测提供技术支撑和理论基础。

β-内酰胺类抗生素是目前使用最广泛的抗生素，因过量使用会导致抗性基因广泛传播，严重威胁了生态环境安全和人类健康，因此其抗性菌已经成为环境中不容忽视的污染物。但是，目前尚缺少高灵敏性、高选择性和快速的检测技术。本项目结合石墨烯基材料、金属有机骨架纳米片材料和生物分子识别技术，开发了一系列基于石墨烯-特异性适配体的比色传感方法，特别是通过筛选获得对β-内酰胺类抗生素抗性菌的标志物PBP2a具有特异性识别的适配子，结合该适配子特异性识别能力及石墨烯-纳米金复合物(Gr-AuNPs)可视化传感性能，实现了抗性菌的灵敏、特异性的检测。进一步探索了该方法的通用性，通过更换识别元件实现了对其他目标物的检测，提升了该传感方法的适用领域和实际意义。本研究结果可为β-内酰胺类抗生素抗性菌的检测提供重要技术支撑。