Department of Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, P. R. China.
Department of Pharmaceutical Analysis, School of Pharmacy, Air Force Medical University, Xi'an 710032, P. R. China.
ACS Appl Mater Interfaces. 2021 Jan 13;13(1):1277-1287. doi: 10.1021/acsami.0c19651. Epub 2021 Jan 4.
Selective discrimination and lasting tracking of live bacteria are primary steps for microbiology research and treatment of bacterial infection. However, conventional detection methods, such as the gold standard of Gram staining, are being challenged under actual test conditions. Herein, we provided a novel method, namely, three excitation peaks and single-color emission carbon quantum dots (T-SCQDs) for the rapid (5 min) peptidoglycan-targeting discrimination of Gram-positive bacteria and lasting tracking (24 h) through one-step staining. Bacterial viability testing indicates that T-SCQDs can achieve nondestructive identification of Gram-positive bacteria within 50-500 μg mL. Interestingly, the fluorescence imaging system suggests that T-SCQDs can also selectively distinguish the type of colonies based on fluorescence intensity. Furthermore, T-SCQDs were successfully used to visually distinguish Gram-positive bacteria from the microbial environment of A549 cells by confocal fluorescence microscopy. These properties endow T-SCQDs with excellent functions for the diagnosis of infection and other biological applications.
选择性识别和持续跟踪活细菌是微生物学研究和细菌感染治疗的主要步骤。然而，在实际测试条件下，传统的检测方法，如革兰氏染色的金标准，正受到挑战。在此，我们提供了一种新方法，即三激发峰和单颜色发射碳量子点（T-SCQDs），用于革兰氏阳性菌的快速（5 分钟）肽聚糖靶向识别和通过一步染色进行持续跟踪（24 小时）。细菌活力测试表明，T-SCQDs 可以在 50-500μgmL 范围内实现对革兰氏阳性菌的非破坏性鉴定。有趣的是，荧光成像系统表明，T-SCQDs 还可以根据荧光强度选择性地区分菌落类型。此外，T-SCQDs 还成功地通过共聚焦荧光显微镜用于可视化区分 A549 细胞微生物环境中的革兰氏阳性菌。这些特性使 T-SCQDs 具有出色的感染诊断和其他生物学应用功能。
