High performance portable sensor based on excellent conductive composite MXene@Ag-MEL for detection of gallic acid in foods.

Abstract

Rapid and accurate detection of bioactive phenolic compounds in food is crucial for assessing nutritional value and ensuring quality. Gallic acid (GA) is a naturally occurring polyphenolic compound found in plant-based foods such as grapes, mangoes, and tea leaves. It possesses significant antioxidants, antibacterial, and anticancer properties, making it a key target in research on food nutrition and functional components. However, many sensors are limited by slow surface dynamics, so the development of advanced sensing materials is a great challenge. In this study, a high specific surface area MEL zeolite (MEL) is prepared (471.24 m2 g-1) and complexed with highly conductive Ag species and two-dimensional MXene nanosheets (MXene) to construct a novel screen-printed sensing platform (MXene/Ag/MEL/chitosan (CS)/screen-printed electrode (SPE). The novel sensor notably possessed excellent GA detection performance, exhibiting an extremely low limit of detection (LOD = 0.5 μM) and a wide detection range (1 μM-50 mM). Further, a portable GA sensing system is prepared by integrating the above screen-printed platform with miniaturized circuits, which showed similar analytical results to the standard high-performance liquid chromatography (HPLC) method (the recovery rate ranges from 95.75% to 97.93%). This work not only presents advanced sensing material but also provides a practical and convenient platform for rapid food analysis and dietary assessment.