Guar Gum Supported ZIF-8 as an Effective Catalyst for Electrochemical Sensing of Gallic Acid in Liquid Food Samples

Abstract

Monitoring of food-based products is mandatory in recent days as a result of increasing health-related issues and to produce ready-to-eat foods. Generally, in the food industry, the antioxidant property of phenolic compounds is utilized to improvize human health. Gallic acid (GA) is a widely known and abundant phenolic acid found used in numerous foods because of its huge health benefits. So far, many methods have been developed for the detection of GA using diverse nanocomposites. Likewise in the view of providing a simple and inexpensive material, we propose a zeolitic imidazolate framework (ZIF-8) functionalized with guar gum (GG) towards GA sensing. Here, the composite is prepared in a very easy and time-efficient manner using biocompatible GG. The physiochemical properties confirm the material formation due to the electrostatic interaction between the zinc ion of ZIF-8 and GG's hydroxyl or carboxyl groups. Morphological studies confirm the nanostructured rhombic dodecahedral ZIF-8 particles embellished on the surface of GG's microlayers. Further, electrochemical studies reveal the composite excellent behaviuor towards the GA sensing with a wide linear range of 200 nM-2.5 mM and a detection limit (LOD) of 60 nM. In addition to this, the composite offers significant selectivity, and good stability of up to 84% for 100 cycles along with acceptable repeatability and reproducibility. Finally, the investigation of the practical utility of unspiked wine, grape juice and tea samples also profound the composite's exceptional sensing with remarkable recovery. Considering all these results, the proposed ZIF-8@GG composite can be fit for the fabrication of sensor devices towards food product testing in industries.