A molecular imprinted ratiometric fluorescence sensor based on blue/orange MXene quantum dots for visual detection of histamine.

Histamine is a highly toxic biogenic amine in food, making its sensitive and rapid detection methods vital for the assurance of edible safety and human health. Here, we explored for the first time a smartphone-enabled ratiometric imprinted fluorescence sensor based on blue/orange MXene quantum dots (MQDs) for fluorescence and visual detection of histamine. A linear relationship between the concentration of histamine and the fluorescence response of the sensor was found in the range of 1-60 μM with a limit of detection (LOD) of 21.9 nM for fluorescence detection and 92.2 nM for visual detection. In addition, the method was validated for the detection of real samples with excellent recoveries from 96.52% to 105.32%. Therefore, this work greatly expands the application of MQDs in the fluorescence sensing field, as well as provides a visual strategy for in-situ detection of histamine in food.