State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
Nanoscale. 2017 Jul 6;9(26):9056-9064. doi: 10.1039/c7nr01975k.
Imaging biofilm-encased microorganisms is challenging due to them being shielded by a sticky and strong extracellular polymeric substance matrix that blocks the penetration of dyes, but is especially important for biofilm study. Here, carbon dots, namely CDs-605, were used for successfully imaging biofilm-encased microorganisms. We demonstrated that such CDs-605 could be easily synthesized from L. plantarum by one-step hydrothermal carbonization. The negatively charged CDs-605 were composed of C, H, O, N, P, and S and contained various functional groups, including -OH, -COOH, and -CONH-. For the first time, CDs-605 were found to be capable of imaging biofilm-encased microorganisms, including E. coli, S. oneidensis, P. aeruginosa, S. aures, and T. reesei, demonstrating that the labeling is universal. The labeling method based on CDs-605 did not require incubation, protection from light, or washing, which makes it very convenient. Additionally, CDs-605 did not disturb the biofilm and displayed better photostability compared to the commercial counterpart. CDs-605 can serve as a simple, yet powerful staining agent for biofilm-embedded microorganism imaging, which is vital for gaining a fundamental understanding of biofilm formation and dispersal.
由于微生物被粘性强的胞外聚合物基质所包裹，染料难以渗透，因此对其进行成像具有挑战性，但这对于生物膜研究尤为重要。在这里，我们使用碳点（即 CDs-605）成功地对生物膜包裹的微生物进行了成像。我们证明，这种 CDs-605 可以很容易地通过一步水热碳化从 L. plantarum 中合成。带负电荷的 CDs-605 由 C、H、O、N、P 和 S 组成，含有各种官能团，包括-OH、-COOH 和-CONH-。首次发现 CDs-605 能够对包括大肠杆菌、S. oneidensis、铜绿假单胞菌、金黄色葡萄球菌和里氏木霉在内的生物膜包裹的微生物进行成像，表明这种标记是通用的。基于 CDs-605 的标记方法不需要孵育、避光和洗涤，非常方便。此外，与商业对照相比，CDs-605 不会干扰生物膜，且具有更好的光稳定性。CDs-605 可以作为一种简单而强大的生物膜包裹微生物成像染色剂，对于深入了解生物膜的形成和分散至关重要。
