The growing concern about nutrient-rich diets and health monitoring has motivated the search for simple, fast, and effective methods for detecting important nutrients in foodstuffs. In this scenario, colorimetric detection using nanostructures presenting enzymatic properties (nanozymes) has gained prominence due to its experimental simplicity and low cost. In this work, zinc oxide–cobalt oxide electrospun nanofibers (ZnO–Co₃O₄ NFs) were combined with titanium carbide (Ti₃C₂T_x) MXene for the colorimetric detection of ascorbic acid. The nanocomposite (ZnO–Co₃O₄ NFs/Ti₃C₂T_x) presented peroxidase-like activity with a high affinity for the chromogenic substrate 3,3,5,5-tetramethylbenzidine and fast reaction kinetics. Taking advantage of the catalytic properties of the developed nanocomposite, ascorbic acid was detected with high sensitivity (the limit of detection was 0.58 μmol L^–1) and selectivity, even in the presence of common interferents. The colorimetric sensor even detected ascorbic acid in orange juice, revealing its potential to be used as a reliable and sensitive portable method for food analysis.

中文翻译：

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具有类过氧化物酶活性的 ZnO–Co3O4 纳米纤维/MXene 复合材料用于抗坏血酸检测

人们对营养丰富的饮食和健康监测的日益关注促使人们寻找简单、快速、有效的方法来检测食品中的重要营养素。在这种情况下，使用具有酶特性的纳米结构（纳米酶）进行比色检测由于其实验简单且成本低廉而受到重视。在这项工作中，氧化锌-氧化钴电纺纳米纤维（ZnO-Co ₃ O ₄ NFs）与碳化钛（Ti ₃ C ₂ T _x）MXene结合用于抗坏血酸的比色检测。纳米复合材料（ZnO–Co ₃ O ₄ NFs/Ti ₃ C ₂ T _x）表现出类似过氧化物酶的活性，对显色底物3,3,5,5-四甲基联苯胺具有高亲和力和快速反应动力学。利用所开发的纳米复合材料的催化特性，即使存在常见干扰物，也能以高灵敏度（检测限为0.58 μmol L ^–1 ）和选择性检测抗坏血酸。该比色传感器甚至检测到橙汁中的抗坏血酸，揭示了其作为可靠且灵敏的便携式食品分析方法的潜力。