Due to small size, strong fluorescence and low cytotoxicity, fluorescent carbon dots (CDs) attract people's attention. The CDs-Ws derived from Weissella sp. Kl-3 with bright blue photoluminescent were obtained via hydrothermal method. The CDs-Ws could selectively label dead bacterial and yeast cells, and show the potential for the differentiation of live/dead microbe. It showed that the prepared CDs-Ws had multicolor fluorescence emission properties, excellent biocompatibility and low biotoxicity with cell and in vivo imaging. In addition, CDs-Ws sensitized by ampicillin sodium was employed as fluorescence nanosensor (CDs-Ws-Amp Na) to detect Cr(VI) and VB₁₂ based on inner filter effet mechanism. The linear correction was obtained for VB₁₂ detection in 0–25 μM with 51.50 nM detection limit, and the linear range was 0–50 μM with 106.57 nM detection limits for Cr(VI) by CDs-Ws-Amp Na. The fluorescent nanosensor was used for detection of Cr(VI) in water and VB₁₂ in serum and milk. It shows excellent potential in bioimaging, Cr(VI) and VB₁₂ detection.

由于尺寸小，荧光强度高和细胞毒性低，荧光碳点（CD）引起了人们的注意。CD- Ws来自Weissella sp.。通过水热法获得具有亮蓝色光致发光的K1-3。CDs- Ws可以选择性标记死亡的细菌和酵母细胞，并显示出活/死微生物分化的潜力。结果表明，所制备的CDs- Ws具有多色荧光发射特性，具有优异的生物相容性，并且通过细胞和体内成像具有较低的生物毒性。此外，氨苄青霉素钠敏化的CDs- Ws被用作荧光纳米传感器（CDs- Ws- Amp Na）以检测Cr（VI）和VB₁₂基于内部过滤器有效机制。通过CDs- Ws- Amp Na对Cr（VI）进行的VB ₁₂检测，在0-25μM，检测限为线性的校正范围为0-50μM，对于Cr（VI），检测限为106.57 nM。荧光纳米传感器用于检测水中的Cr（VI）和血清和牛奶中的VB ₁₂。它在生物成像，Cr（VI）和VB ₁₂检测中显示出极好的潜力。