A new highly sensitive fluorescent probe for fluorescence sensing of formaldehyde in living cells/food samples.

Formaldehyde (FA), which is widely used in construction, pharmaceutical, and food industries, ranks among the top three indoor pollutants. As living standards improve, public awareness of food safety has gradually increased. Therefore, it is crucial for human health to find a simple and effective method for detecting FA levels in food. In this work, a new highly sensitive FA fluorescent probe, named LTY, is reported. When reacting with FA, the probe LTY produces an intense fluorescent signal due to the disruption of the PET effect. The probe LTY has been successfully used to image FA in living cells. In addition, by performing RGB analysis of food supernatants with smartphone APPs, a relationship between fluorescence intensity and FA concentration was established, which could easily indicate the amount of FA in food products. This work is promising to provide an effective strategy for simple and timely detection of FA content in food products.