A Golgi-targeted regenerated fluorescence probe for the detection of formaldehyde and its imaging applications in living cells and zebrafish.

Formaldehyde (FA) is an important carbonyl compound. Although formaldehyde plays a significant role in intracellular signal transduction and maintaining homeostasis, excessive intake of formaldehyde can lead to its accumulation in the body, causing various diseases. Therefore, the concentration of formaldehyde associated with various diseases, and the determination of the formaldehyde content in the body is of great significance for studying the mechanisms of diseases and diagnosis. A Golgi-targeted regenerative FA fluorescent probe was constructed in this manuscript. After the probe reacted with FA, it caused a 6-exo-trig intramolecular lactam ester exchange, then released a fluorophore with the enhanced fluorescence signal, and realized the detection of FA simultaneously. It showed high sensitivity and selectivity in the detection of FA, with a detection limit as low as 0.18 μM. More importantly, the probe can release formaldehyde after reacting with formaldehyde, so it will not cause fluctuations in the original formaldehyde concentration. This probe had been successfully utilized to visualize endogenous and exogenous FA in the Golgi apparatus of HeLa cells and zebrafish. The probe is expected to become a powerful tool for studying the function of FA in organisms especially in the Golgi apparatus.