Intracellular pH has been associated with multiple biological processes. However, fluorescent probes for pH are limited. Herein, a new pH fluorescent probe was developed based on reversible structural changes. This probe provided three reversible pH response modes within 2.00–12.00. Under the acidic conditions, there is no-fluorescence, under the neutral conditions, the emission is at 650 nm, under the alkaline conditions, the emissions at 650 nm decreases and at 460 nm appears and increases simultaneously. The probe solution presented distinct colors response to the pH values from 2.00 to 12.00. The fluorescent response from pH 2.00–12.00 makes the probe suitable for the monitoring pH in living cells. Moreover, the imaging results confirm that probe S can be applied in fluorescence imaging in living cells.

细胞内 pH 值与多种生物过程有关。然而，用于 pH 的荧光探针是有限的。在此，基于可逆结构变化开发了一种新的 pH 荧光探针。该探针在 2.00–12.00 范围内提供了三种可逆的 pH 响应模式。酸性条件下无荧光，中性条件下650 nm发射，碱性条件下650 nm发射减少，460 nm发射同时出现和增加。探针溶液对 2.00 至 12.00 的 pH 值呈现出不同的颜色响应。pH 2.00–12.00 的荧光响应使探针适用于监测活细胞中的 pH。此外，成像结果证实探针S可应用于活细胞荧光成像。