Total antioxidant capacity (TAC) can be evaluated by detecting the content of antioxidants, such as ascorbic acid, based on the enzyme-mimetic activity of nanomaterials. Herein, we fabricated a 3D-V₂O₅/NC nanocomposite using a self-templating strategy, which achieved ultrafine particles (∼2.5 nm), a porous carbon layer, large specific surface area (152.4 m²/g), N-doping and heterogeneous structure. The strong catalytic activity of 3D-V₂O₅/NC resulted from the integrated effect between the ultrafine structure of V₂O₅ nanoparticles and the 3D porous nitrogen-doped carbon framework, effectively increasing the number of active sites. This nanozyme presented a higher catalytic activity than its components or precursors in the nanocomposite (e.g., VN/NC, NC, V₂O₅, and VO₂/g-C₃N₄). ROS scavenging experiments confirmed that the dual enzyme-like activity of 3D-V₂O₅/NC (catalase-like and oxidase-like) resulted from their co-participation of ‧O₂⁻, h⁺ and ‧OH, among which ‧O₂⁻ played a crucial role in the catalytic color reaction. By virtue of the 3D-V₂O₅/NC nanoenzyme activity and TMB as a chromogenic substrate, the mixed system of 3D-V₂O₅/NC + TMB + H₂O₂ provided a low detection limit (0.03 μM) and suitable recovery (93.0–109.5%) for AA. Additionally, a smartphone-based colorimetric application was developed employing "Thing Identify" software to evaluate TAC in beverages. The colorimetric sensor and smartphone-detection platform provide a better or comparable analytical performance for TAC assessment in comparison to commercial ABTS test kits. The newly developed smartphone-based colorimetric platform presents several prominent advantageous, such as low cost, simple/rapid operation, and feasibility for outdoor use.

基于纳米材料的酶模拟活性，可以通过检测抗坏血酸等抗氧化剂的含量来评估总抗氧化能力 (TAC)。在此，我们使用自模板策略制备了 3D-V ₂ O _{5 /NC 纳米复合材料，实现了超细颗粒（~2.5 nm）、多孔碳层、大比表面积（152.4 m} ² /g）、N-掺杂和异质结构。_{3D-V 2} O ₅ /NC的强催化活性是V ₂ O _{5超细结构之间的综合效应}纳米粒子和 3D 多孔氮掺杂碳框架，有效地增加了活性位点的数量。_{该纳米酶呈现出比纳米复合材料中其组分或前体（例如，VN/NC、NC、V 2} O ₅和VO ₂ /gC ₃ N ₄）更高的催化活性。_{ROS清除实验证实，3D-V 2} O ₅ /NC的双重类酶活性（catalase-like和oxidase-like）是由于‧O ₂ ⁻、h ⁺和‧OH的共同参与，其中‧ O ₂ ^-在催化显色反应中起着至关重要的作用。凭借3D-V ₂O _{5 /NC纳米酶活性和TMB作为显色底物，3D-V 2} O ₅ /NC + TMB + H ₂ O ₂的混合体系提供了低检测限（0.03 μM）和合适的回收率（93.0–109.5%）对于AA。此外，还开发了基于智能手机的比色应用程序，使用“Thing Identify”软件来评估饮料中的 TAC。与商业 ABTS 测试套件相比，比色传感器和智能手机检测平台为 TAC 评估提供了更好或相当的分析性能。新开发的基于智能手机的比色平台具有成本低、操作简单/快速、户外使用可行性等几个突出优势。