多功能纳米微球检测牙龈卟啉单胞菌的实验研究

An experimental study on the detection of Porphyromonas gingivalis with multifunctional nanospheres

目的:建立基于磁编码微球和上转换荧光编码微球灵敏性检测牙龈卟啉单胞菌的新方法。方法:用溶胶凝胶法分别制备磁编码微球和上转换荧光编码微球,与牙龈卟啉单胞菌单克隆抗体结合后捕捉牙龈卟啉单胞菌、具核梭杆菌、变形链球菌混合菌液中的牙龈卟啉单胞菌。用外置980 nm近红外激光器的荧光显微镜、透射电镜及扫描电镜评估该法的检测效果。结果:制备的磁编码微球及上转换荧光编码微球的分散性好、粒径均匀、形貌均一,磁编码微球的磁性较强,上转换荧光编码微球的荧光强度较高;混合菌液中纳米微球可特异性捕捉牙龈卟啉单胞菌,检测极限为10 CFU/ml。结论:本实验所建立的检测系统可灵敏检测混合菌液中的牙龈卟啉单胞菌。

Objective： To development a new method for sensitive detection of Porphyromanus gingivalis （P. gingivalis） based on magnetic encoding nanospheres and upconversion fluorescent encoding nanospheres. Methods： Magnetic and upconversion fluorescent encoding nanospheres were prepared by sol-gel method respectively, combined the monoclonal antibodies specific to P. gingivalis after modifying the surface of nanospheres. The system was used to detect P. gingivalis from mixed bacteria solution of P. gingivalis, F. nu- cleatum and S. mutans. Fluorescent microscopy with an external 980 nm near-infrared light pulse laser, scanning and transmission mi- croscope were used to evaluate the effectiveness of the detection system. Results： Magnetic and upconversion encoding nanospheres had better dispersion, particle size uniformity and homogeneous morphology. Besides, the magnetic encoding nanospheres had good magnetic properties and strong fluorescence intensity. P. gingivalis was captured by magnetic and upconversion encoding nanospheres in a mixed solution of the 3 bacteria with a detection limit of 10 CFU/ml. Conclusion： The method designed in this study can capture P. gingivalis sensitively in a mixed bacteria liquid.