Rapid response to amine vapor based on fluorescent light-up sensor for real-time and visual detection of crawfish and fish freshness

Biogenic amines are generally produced from the degradation of amino acids in biometabolism, which can be used as an important biomarker for food spoilage. Rapid, simple and accurate detection of biogenic amines is an important task for the food safety. Here we synthesize a series of coumarin hydrozone derivatives with high solid-state emission. BDCH2 exhibits a fluorescent switch between the yellow emission (λem,max = 555 nm) and the NIR region (λem,max = 720 nm) upon HCl/NH3 vapor stimuli. The response time for NH3 vapor is only 2 s. Utilizing this property, BDCH2 as a biogenic amine vapors sensor can be readily applied in the detection of food spoilage for real-time and visual monitoring the freshness of crawfish and fish with quick response, easy visualization and simple operation. [Display omitted] •Fluorophores exhibit concentration-enhanced fluorescence and high solid-state emission.•Fluorophore can rapid response to NH3 vapor with fine reversibility and processability.•Fluorophore shows a rapid fluorescent switch for real-time and visual monitoring the freshness of crawfish and fish.