Rapid, reliable, and convenient fluorescent probes are of great importance for specifically identifying permanganate and pH in biological systems. In this work, raw materials were provided by malic acid and neutral red for the preparation of red emission carbon dots (RCDs) using a hydrothermal carbonization approach. Superior features of RCDs including good stability, exceptional biocompatibility, and prominent water solubility were found, which enables them to favorably track permanganate and pH. Upon the introduction of permanganate, as-acquired RCDs presented a notable emission enhancement owing to aggregation induced emission (AIE) mechanism. Results indicated that they can act as “turn-on” fluorescent sensor for quantitative analysis of permanganate in the scope of 0–115 μM with a detection limit of 14.5 nM. Most importantly, this probe exhibited a special responsive functionality towards pH, in which a good linearity in the pH range of 6.2–8.2 could be readily realized. Besides, evident color changes of RCDs solution under sunlight can be visualized at different pH, which is more desirable for the fluorescent and colorimetric bimodal sensing of pH. Intriguingly, it was observed that RCDs can successfully target lysosome in living cells. Finally, as-developed RCDs were performed for the label-free, real-time visualization of permanganate and pH fluctuations in vivo and in vitro.

快速、可靠和方便的荧光探针对于特异性识别生物系统中的高锰酸盐和 pH 值非常重要。在这项工作中，原料为苹果酸和中性红，用于使用水热碳化方法制备红色发射碳点（RCDs）。发现了 RCD 的优越特性，包括良好的稳定性、出色的生物相容性和显着的水溶性，这使它们能够很好地跟踪高锰酸盐和 pH 值。引入高锰酸盐后，由于聚集诱导发射（AIE）机制，获得的 RCD 呈现出显着的发射增强。结果表明，它们可以作为“开启”荧光传感器，对 0-115 μM 范围内的高锰酸盐进行定量分析，检测限为 14.5 nM。最重要的是，该探针对 pH 表现出特殊的响应功能，在 6.2-8.2 的 pH 范围内可以很容易地实现良好的线性。此外，在不同的 pH 值下，可以观察到 RCDs 溶液在阳光下明显的颜色变化，这对于 pH 值的荧光和比色双峰传感更为理想。有趣的是，观察到 RCD 可以成功地靶向活细胞中的溶酶体。最后，对开发的 RCD 进行了无标记、实时可视化体内和体外高锰酸盐和 pH 值波动。这对于 pH 的荧光和比色双峰传感更理想。有趣的是，观察到 RCD 可以成功靶向活细胞中的溶酶体。最后，对开发的 RCD 进行了无标记、实时可视化体内和体外高锰酸盐和 pH 值波动。这对于 pH 的荧光和比色双峰传感更理想。有趣的是，观察到 RCD 可以成功靶向活细胞中的溶酶体。最后，对开发的 RCD 进行了无标记、实时可视化体内和体外高锰酸盐和 pH 值波动。