A Fluorescent Metal–Organic Framework for Food Real‐Time Visual Monitoring

Abstract

Due to increasing food‐safety issues, exploiting efficient approaches for food quality assessment and instrumentation has attracted concerns worldwide. Herein, a smart evaluation system based on a fluorescent metal–organic framework (MOF) is developed for real‐time visual monitoring of food freshness. Via post‐synthetic modification, a ratiometric fluorescent MOF probe is constructed by covalently coupling fluorescein 5‐isothiocyanate (5‐FITC) with NH2‐rich lanthanide MOF. The probes exhibit a dual‐emissive‐responsive to biogenic amine, resulting in an increase in FITC emission along with a decrease in Eu3+ emission accompanied by a clear distinguishable color transition from orange red to green. After doping the probes on a flexible substrate, the obtained MOF composite film can be integrated with a smartphone‐based portable platform easily. It is proved that this smart evaluation system can be used for on‐site inspection of the freshness of raw fish samples. This work develops a fluorescent MOF‐based smart evaluation system as a novel platform for application in food monitoring, which not only has enormous economic value but also holds great public health significance.

Red Carbon: a Carbon-Oxygen-based covalent semiconductor for selective amine sensing

“…[25][26][27][28][29] Sensors are of particular interest especially for food safety, which became recently one of the most important global issues. 30 The inappropriate handling and the consumption of spoiled food causes, every year, serious problems to millions of people all over the globe. 30 In many cases, the presence of biogenic amines, such as putrescine or cadaverine produced by the breakdown of amino acids, indicates the microbial spoilage of the food.…”

“…30 The inappropriate handling and the consumption of spoiled food causes, every year, serious problems to millions of people all over the globe. 30 In many cases, the presence of biogenic amines, such as putrescine or cadaverine produced by the breakdown of amino acids, indicates the microbial spoilage of the food. 31 The unpleasant odor of such biogenic amines indicates a high volatility of these compounds, which are therefore detectable by chemical and/or physical sensors.…”

MOF sensors for food safety: ultralow detection of putrescine and cadaverine in protein rich foods

“…It is noteworthy that only a handful of fluorescent sensors have been reported to date for the sensing of biogenic amines. [10][11][12][13][14][15][16][17] Most of these sensors comprise purely organic materials. [10][11][12][13][14] Porous materials such as metal organic frameworks (MOFs) possessing a high surface area, permanent porosity, and good thermal and chemical stability with tuneable properties are known for various applications.…”

Dual emissive amphiphilic carbon dots as ratiometric fluorescent probes for the determination of critical micelle concentration of surfactants

“…15 This inspired us to develop favourable Cdots as ratiometric uorescent probes. 16,17 In the present work, we constructed environment-sensitive, amphiphilic, dual-color emissive Cdots, which were prepared through a one-step solvothermal method with citric acid (CA) and dodecylamine as raw materials. 18 Because their blue and yellow photoluminescence (PL) are very sensitive to the surrounding media, we explored their potential as ratiometric uorescent probes in the determination of the CMC values of surfactants for the rst time.…”