Si-rhodamines with fine-tuned reactivities for tracking formaldehyde in glioblastoma

Formaldehyde (FA), an essential signaling molecule and an emerging neurotoxin in the brain, regulates various physiological and pathological processes. The abnormal metabolism of FA is associated with extensive brain diseases, including glioblastoma. However, FA probes with systematically fine-tuned reactivities are still very challenging. A group of silicon-substituted rhodamine-based FA probes was designed with fine-tuned structures and FA activities for tracking FA in vivo. With systematic structural manipulation, we have quantitatively revealed the chemical origins of the distinct FA reactivities in probes. Moreover, we successfully tracked the dynamic of FA in live cells, organs, and live animals by the designed probe. The vivid upregulation of FA in heterotopic xenografted and orthotopic glioblastoma by fluorescence imaging with the designed FA probe has proved that FA can be a potential molecular marker for glioblastoma.