Aggregation-Induced Emission-Based Fluorescence Probe for Fast and Sensitive Imaging of Formaldehyde in Living Cells

[Image: see text] Formaldehyde (FA), as a reactive carbonyl species and signaling molecule, plays an important role in living systems. Here, an FA-responsive probe with fast response and great selectivity is designed based on aggregation-induced emission. The probe is prepared by functionalizing tetraphenylethene (TPE) with two amine groups. FA is detected based on the solubility differences between the amine-functionalized TPE and the corresponding Schiff bases after reaction with FA. The probe exhibits a limit of detection of 40 nM and a response time of ∼90 s. Furthermore, its ability to detect both endogenous and exogenous FA is demonstrated in living cells with high specificity. Moreover, the probe is also introduced to image endogenous FA in real time with fast response. These results suggest that our probe holds great potential for tracking FA in living systems under various physiological conditions as well as related biomedical applications.