Meat's freshness is closely related to food safety and human health and has received increasing attention nowadays. To on-site visually screen meat freshness in a fast and non-destructive manner, we rationally constructed a series of fluorescent probes (JDCN, JDNS, and JDPY) with distinct electron-withdrawing substitution groups based on julolidine-fused coumarin. These probes underwent an aza-Michael addition followed by an elimination reaction with cadaverine to generate a colorimetric and ratiometric fluorescence response, and their sensing performance was rationally enhanced by improving the electron-withdrawing strength of substitution groups. Particularly, JDCN with a dicyanovinyl group as the reaction site exhibited outstanding sensing performance including rapid response (∼60 s), high selectivity, and low detection limit (14 nM). Furthermore, JDCN was fabricated into test kits to detect cadaverine vapor with a high-contrast fluorescence change from red to green. Based on two-color visualization of cadaverine vapor, on-site non-contact and non-destructive monitoring of meat freshness was successfully achieved. The good sensing performance rendered JDCN test kits a promising real-time fluorescence screening platform for rapid, non-destructive, and accurate evaluation of meat freshness.
Bibliographical noteFunding Information:
This work was sponsored by the National Natural Science Foundation of China (nos. 22168009 and 21978222) and the Natural Science Foundation of Guangxi (no. 2020GXNSFDA297030). This work was also supported by the National Research Foundation of Korea (NRF) (CRI Project no. 2018R1A3B1052702 and 2019M3E5D1A01068998 for J.S.K. and 2022R1C1C2007637 for S.K.).
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ASJC Scopus subject areas
- Analytical Chemistry