Chao Peng,Xinyu Ma,Dan Lin,Xiaowen Feng,Huan Yu,Yinhui Li
Mitophagy , a specialized form of autophagy, holds the key to cellular metabolism and physiology. Viscosity is a significant marker for visualization of the mitophagy process in real-time. Hence, development of well-performing viscosity probe is beneficial to study mitophagy-related dynamic physiological and pathological processes. Here, a new strategy was proposed by combination of AIE property and molecular rotors to design novel viscosity probe. The probe named TPA-Py was obtained by Knoevenagel condensation reaction of AIE unit and pyridine salt, which giving the probe excellent near-infrared emission, good water-solubility and mitochondrial targeting ability. Most importantly, TPA-Py owns two rotatable parts of triphenylamine and double bond , enabling the probe to equip with AIE property and sensitive recognition units for viscosity. With the environmental viscosity increasing, the rotation of the molecular rotor and the AIE unit is restricted effectively, the probe displayed strong fluorescence. Then, TPA-Py was successfully employed for monitoring the mitophagy process in A549 cells by imaging viscosity alterations. As mitophagy constitutes an important consideration in the pathogenesis of drug-induced liver injury, TPA-Py was also applied to explore the variation of viscosity in production and remediation pathways of APAP-induced liver injury. These results demonstrated that TPA-Py was a highly sensitive viscosity probe which holds great potential of biological applications.
Mitochondria, the primary energy-producing organelles, critically regulate cellular activities. Their internal viscosity—a key microenvironmental parameter—directly affects material transport and energy conversion, with aberrant levels linked to disease pathogenesis. Most reported mitochondrial viscosity probes were susceptible to polar interference, resulting in insufficient specificity for viscosity detection. This study designed and developed a novel polar-insensitive fluorescent probe, Y-CN , based on a phenothiazine skeleton - a small molecular compound with excellent fluorescent properties. The experimental data revealed an excellent linear relationship (R 2 > 0.99) between Y-CN 's fluorescence intensity and viscosity over a wide range from 1.005 to 219 cP. When viscosity increased from 1.005 cP (aqueous buffer) to 219 cP, Y-CN demonstrated a dramatic 209-fold fluorescence amplification. Furthermore, the probe exhibited excellent selectivity, pH stability, and low toxicity. Moreover, Y-CN could detect viscosity changes induced by food thickeners. Y-CN successfully monitored dynamic changes in mitochondrial viscosity within live cells, providing a powerful tool for specific investigation of mitochondria-associated physiological and pathological processes, with significant potential for biological applications.
危险品化学品经营许可证（带存储）