A hydrothermal method has been employed to synthesize a green and one-pot carbon dots-based sensor for ratiometric monitoring and imaging lysosomal pH in living cells. The carbon dots were directly functionalized by abundant amino groups during synthesis and exhibited dual emission bands at 439 and 550 nm under single-wavelength excitation of 380 nm without any additional modification. In addition to its small size, the established sensor had good biocompatibility. Owing to its abundant amino groups and good hydrophilicity, the sensor is able to target lysosome with high Pearson’s colocalization coefficients (0.935 and 0.924) and responds to change of lysosomal pH in living cells. It also had excellent pH sensitivity and reversibility, and anti-interference capability, thus enabling sensing pH change in intracellular environment in real time, as demonstrated by successful monitoring of lysosomal pH changes during lysosomal alkalization, dexamethasone-induced stimulation, and stress in Michigan Cancer Foundation-7 cells (blue channel, excitation = 405 nm and emission = 419–459 nm bandpass; and yellow channel, excitation = 405 nm and emission = 530–570 nm bandpass). Graphical abstract Graphical abstract

中文翻译：

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基于一锅合成碳点的溶酶体靶向比率荧光传感器用于监测活细胞中的 pH 值

已采用水热法合成绿色和单锅碳点传感器，用于活细胞中的比例监测和溶酶体 pH 成像。碳点在合成过程中被丰富的氨基直接官能化，并在 380 nm 的单波长激发下在 439 和 550 nm 处表现出双发射带，无需任何额外修饰。除了体积小之外，所建立的传感器还具有良好的生物相容性。由于其丰富的氨基和良好的亲水性，该传感器能够以高 Pearson 共定位系数（0.935 和 0.924）靶向溶酶体，并对活细胞中溶酶体 pH 值的变化做出响应。它还具有优异的pH敏感性和可逆性以及抗干扰能力，从而能够实时感知细胞内环境的pH变化，正如在密歇根癌症基金会-7 细胞中成功监测溶酶体碱化、地塞米松诱导的刺激和应激期间溶酶体 pH 变化所证明的那样（蓝色通道，激发 = 405 nm，发射 = 419–459 nm 带通；黄色通道，激发 = 405 nm 和发射 = 530–570 nm 带通）。图形摘要图形摘要