A new bioluminescent probe for detecting formaldehyde in real food samples.

Formaldehyde (FA) is an important type of reactive carbonyl species (RCS). The development of a rapid and efficient method to quantify FA in food and biological samples is necessary. Herein, we have developed the first bioluminescent probe FA-Fluc with homoallyl amine to cage firefly D-luciferin (Fluc), which could react almost completely with FA via aza-Cope rearrangement in 4 h to afford a turn-on Bioluminescence (BL). The detection limit of FA-Fluc was 0.047 ppm; and could detect FA in different seafood, agricultural products, and cooking processes. FA-Fluc has a good selectivity for FA, which shows that it does not react with other RCS. In addition, the FA content detected in complex food substrates is almost the same as that detected by acetylacetone and high-performance liquid chromatography (HPLC) methods. We also found that FA-Fluc was a powerful tool for real-time and dynamic imaging of FA in live cells and animals.