A Bioluminescent Enzyme-Triggered Formaldehyde Donor with High Contrast Bioimaging

• 1、Hunan Provincial Key Laboratory of Cytochemistry, School of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha, 410114

Abstract：High signal-to-noise ratio (SNR) and sensitivity monitoring of formaldehyde delivery in living systems is of great significance for the precise study of the physiological and pathological functions of formaldehyde. However, traditional formaldehyde donors mainly use fluorescent signals to monitor formaldehyde release, which hampers the high-performance bioimaging due to the undesirable background autofluorescence, leading to poor SNR and compromised imaging sensitivity. Herein, we present a bioluminescent formaldehyde donor, B-FAD, for esterase-activated formaldehyde release and high SNR bioluminescence imaging. By protecting the hydroxyl group of D-luciferin with acetoxymethyl ether group, B-FAD cannot be catalyzed by luciferase to emit light. In the presence of esterase, the ester bond of B-FAD breaks, producing formaldehyde and D-luciferin. B-FAD realizes formaldehyde release with high selectivity and high sensitivity to esterase, accompanied by 34 times enhanced bioluminescence. In addition, B-FAD has been successfully applied to formaldehyde release and imaging in living cells, with a SNR about twice higher than fluorescence imaging. Therefore, B-FAD is expected to become an effective tool for studying the function of intracellular formaldehyde.

Keywords： Formaldehyde donor bioluminescence autofluorescence bioimaging