Neuroinflammation is pervasive throughout various neurodegenerative diseases and is regarded as one of the main destructive effects of these diseases. A large quantity of nitric oxide (NO) will be produced by nitric oxide synthase (NOS) in inflammatory cells, and thus has been considered as a favorable index to reflect the level of inflammation. However, NO concentration in cells is commonly affected by neuronal nitric oxide synthase (nNOS), which makes conventional NO sensors unable to accurately evaluate the level of neuroinflammation with high fidelity. Fortunately, during a neuroinflammation process, the significantly increased lipid droplets in brain cells can supply another indicator for evaluating neuroinflammation. Herein, a lipid droplet-targeted two-photon nitric oxide probe (SUN-TAN) was designed for monitoring NO in lipid droplets, thus assessing the level of neuroinflammation with high fidelity. Upon reacting with NO and being excited by near-infrared light at 780 nm, SUN-TAN exhibits an emission peak at 635 nm. The applications of SUN-TAN in NO determination and imaging in both BV-2 cells and brain tissues of mice suffering from neuroinflammation induced by ischemic brain injury have been achieved.

神经炎症普遍存在于各种神经退行性疾病中，被认为是这些疾病的主要破坏性影响之一。炎症细胞中的一氧化氮合酶(NOS)会产生大量的一氧化氮(NO)，因此被认为是反映炎症水平的有利指标。然而，细胞中的 NO 浓度通常受到神经元一氧化氮合酶 (nNOS) 的影响，这使得传统的 NO 传感器无法高保真地准确评估神经炎症的水平。幸运的是，在神经炎症过程中，脑细胞中显着增加的脂滴可以为评估神经炎症提供另一个指标。在此，设计了一种脂滴靶向双光子一氧化氮探针（SUN-TAN），用于监测脂滴中的 NO，从而以高保真度评估神经炎症的水平。与 NO 反应并被 780 nm 的近红外光激发后，SUN-TAN 在 635 nm 处显示出发射峰。SUN-TAN在缺血性脑损伤诱导的神经炎症小鼠BV-2细胞和脑组织中NO测定和成像中的应用已经实现。