Efficient imaging based on P - and N-codoped carbon dots for tracking division and viability assessment of lactic acid bacteria

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 223; p. 113155
• Main Authors: Fu, Tianxin, Wan, Yang, Jin, Furong, Liu, Buwei, Wang, Jindi, Yin, Xinyue, Fu, Xiangbo, Tian, Bo, Feng, Zhibiao
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2023
• Subjects: Carbon; Carbon dots; Division state; Fermented juices; Fluorescent Dyes; LAB viability; Lactobacillales; Nitrogen; Optical Imaging; Quantum Dots; Fermented juices; LAB viability; Carbon dots; Division state
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2023.113155

Assessment of lactic acid bacteria (LAB) activity plays a key role in the fermented food industry. Fluorescence imaging method based on dye is facile to detect LAB viability. However, it is difficult to obtain stable fluorescence, non-toxic and low-cost dyes. In this study, we prepare P- and N-doped carbon dots (PN-CDs) via microwave-assisted hydrothermal synthesis. The properties of high quantum yield (60.36%) and excitation dependence allowed for multicolor imaging of LAB (Lactobacillus plantarum [L.p] and Streptococcus thermophilus [S.t]). The abundant functional groups and positive charges (+2.34 mV) on the surface of PN-CDs facilitated their quickly integrated into cell wall of live LAB with obvious fluorescence or into dead cells. As a result, PN-CDs can not only be used to rapidly and efficiently monitor bacterial viability (one minute), but can also be used to visualize LAB division using fluorescence imaging. Importantly, the PN-CDs have potential to rapidly detect LAB activity in LAB-fermented juices. [Display omitted] •The preparation of PN-CDs can be used for multi-color imaging of LAB.•The PN-CDs can track the division state of LAB.•By PN-CDs staining can quickly distinguish between dead/live LAB in short time.•The PN-CDs can rapidly detect LAB activity in LAB-fermented juices.