In analytical science, it is always of great scientific and practical significances to explore convenient, rapid, and reliable methods/devices to trace the H₂O₂ level in various matrices. Herein, we fabricated a ready-to-use paper-based chemosensor by using mesoporous carbon-dispersed Pd nanoparticles (Pd NPs/meso-C) as a promising peroxidase mimic for the visual determination of H₂O₂. Thanks to the large exposed surface of the meso-C support and the highly dispersed active Pd NPs, the synthesized Pd NPs/meso-C exhibited favorable catalytic performance to trigger the chromogenic reaction of colorless TMB to blue TMBox mediated by H₂O₂, providing a K_cat of 326.67 s⁻¹ for H₂O₂ and 0.55 s⁻¹ for TMB, larger than the bare Pd NPs and even comparable to the activity of natural horse radish peroxidase. As demonstrated, this principle could be employed to colorimetrically detect H₂O₂ in the linear scope of 5–300 μM. By simply immobilizing the Pd NPs/meso-C mimic and the TMB substrate onto a common filter paper, ready-to-use paper-based sensors were further prepared. By combining these test strips with a smartphone and an easy-to-access color-scanning APP together, the integrated platform could be used for the quantitative analysis of H₂O₂ with advantages of simple operation, fast response, low cost, and good selectivity and repeatability. Furthermore, reliable sensing of the target in milk matrices suggested great promise of the integrated platform in practical applications.

在分析科学中，探索便利，快速和可靠的方法/设备来追踪各种基质中H ₂ O _2的含量始终具有重大的科学和实践意义。在这里，我们通过使用介孔碳分散的Pd纳米颗粒（Pd NPs / meso-C）作为有希望的过氧化物酶模拟物，用于目测H ₂ O ₂，制造了一种现成的基于纸张的化学传感器。由于内消旋C载体的暴露表面较大且活性Pd NPs高度分散，因此合成的Pd NPs /内消旋C表现出良好的催化性能，可触发无色TMB发生发色反应，由H ₂ O ₂介导为蓝色TMBox ，提供一只K_猫H ₂ O ₂为326.67 s ^-1，TMB为0.55 s ^-1，大于裸露的Pd NPs，甚至与天然辣根过氧化物酶的活性相当。如图所示，该原理可用于比色法检测5–300μM线性范围内的H ₂ O ₂。通过简单地将Pd NPs / meso-C模拟物和TMB底物固定在普通滤纸上，可以进一步制备现成的纸基传感器。通过将这些测试条与智能手机和易于访问的彩色扫描APP结合在一起，集成平台可用于H ₂ O ₂的定量分析具有操作简单，响应速度快，成本低，选择性和重复性好等优点。此外，对牛奶基质中目标物的可靠检测表明该集成平台在实际应用中具有广阔的前景。