An activated fluorescent probe to monitor NO fluctuation in Parkinson's disease

The imbalance of nitric oxide (NO) homeostasis in the brain is closely related to the occurrence of Parkinson's disease (PD). Therefore, revealing the fluctuation of NO in brain is crucial for understanding the pathophysiological processes. However, currently developed NO probes are unsuitable for this purpose due to their poor blood-brain barrier permeability. Herein, a fluorescent probe ( PO-NH ) with blood-brain barrier crossing capability and high selectivity for NO was developed. Under the NO mediation, the photoinduced electron transfer (PET) process of the probe was blocked, giving an intensive fluorescence enhancement ( F / F0 = 15). Moreover, PO-NH can be used to effectively monitor changes in intracellular NO levels. Significantly, due to excellent blood-brain barrier crossing ability and near-infrared (NIR) emission, PO-NH is suitable for in vivo imaging of NO in the brain and illustrating with the deterioration of PD, the level of NO gradually increased in the brain of PD mice. We believe that PO-NH may provide a beneficial tool for understanding the biological function of NO in the brain and revealing the complex connection between NO and PD. (c) 2025 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.