A ratiometric fluorescent electrospun film with high amine sensitivity and stability for visual monitoring of livestock meat freshness
Xiaodong Zhai, Yuhong Xue, Wenjun Song, Yue Sun, Tingting Shen, Xinai Zhang, Yanxiao Li, Fuyuan Ding, Di Zhang, Chenguang Zhou, Muhammad Arslan, Haroon Elrasheid Tahir, Zhihua Li, Jiyong Shi, Xiaowei Huang, Xiaobo Zou
Abstract
Ratiometric fluorescent films with high amine sensitivity and stability were developed to monitor the freshness of beef and pork. Fluorescein isothiocyanate (FITC) and red carbon quantum dots (R-CQD) were used as the amine-responsive indicator and internal reference, respectively. The electrospun films prepared by immobilizing FITC and R-CQD complex (F-R) into polyvinylidene fluoride (PVDF) under 35 %, 55 % and 75 % of relative humidity (RH) were named F-R@PVDF-1, F-R@PVDF-2 and F-R@PVDF-3, respectively. In comparison, the F-R@PVDF-2 film exhibited the highest sensitivity to trimethylamine (TMA), demonstrating a limit of detection (LOD) value of 1.59 μM, and meanwhile high stability during storage with ΔE value of 1.99 after 14 days of storage at 4 °C. The F-R@PVDF-2 film also showed a significant fluorescent red-to-brown color change during meat freshness monitoring at 4 °C. Conclusively, this study reported a new ratiometric fluorescent film that can be used to track the freshness of meats in food packaging.