石墨烯薄膜由于其良好的柔韧性和高导电性而被认为是构建自支撑电极的有前途的材料。然而，由原始石墨烯或传统石墨烯片还原氧化石墨烯工艺制成的薄膜限制了电催化性能。装饰活性金属物种或将杂原子掺入石墨烯骨架已被证明是提高石墨烯薄膜自支撑电极电催化效率的有效方法。在此，我们提出了一种由均匀的 Pd 纳米粒子装饰 N,S 共掺杂多孔石墨烯薄膜 (Pd/NSPGF) 组成的独立电极，并通过原位跟踪活体分泌的 H2O2 量来探索其在区分各种人类结肠细胞类型中的实际应用。细胞。我们的研究结果表明，一方面，NSPGF 具有丰富的表面和内部孔隙，促进活性位点暴露和电化学反应过程中的质量扩散；另一方面，用杂原子（例如氮或硫）对石墨烯框架进行替代掺杂可以调整其电子和化学性质，并促进高密度钯纳米粒子的均匀负载。此外，Pd/NSPGF 的内在活性是通过 Pd 纳米颗粒与 NSPGF 支持物的相互作用来调节的。利用形貌和成分的优势，自支撑Pd/NSPGF电极表现出卓越的电化学性能，线性范围高达2.0 mM，检测限低至0.1 μM（S/N = 3），灵敏度高达665 µA cm -2 mM-1，选择性良好。基于Pd/NSPGF的电化学传感系统应用于实时跟踪正常人结肠上皮细胞和人结直肠癌细胞释放的H2O2时，可以通过测试每个细胞释放的细胞外H2O2分子的数量来区分细胞类型。在疾病相关临床标本的早期检测和监测方面具有巨大的潜力。© 2024。作者获得 Springer-Verlag GmbH（Springer Nature 旗下德国公司）的独家许可。

Graphene film has been considered a promising material for the construction of self-supported electrodes due to its favorable flexibility and high conductivity. However, the film fabricated from pristine graphene or conventional graphene sheet reduced graphene oxide processes limited electrocatalytic performance. Decorating active metal species or incorporating heteroatoms into the graphene framework have been proved to be effective methods to enhance the electrocatalytic efficiency of graphene film-based self-supported electrodes. Herein, we present a freestanding electrode composed of uniform Pd nanoparticles decorating N,S co-doped porous graphene film (Pd/NSPGF) and explore its practical application in differentiating various human colon cell types by in situ tracking the amount of H2O2 secreted from live cells. Our findings reveal that, on the one hand, the NSPGF has abundant surface and inner pores, which promote active site exposure, and mass diffusion during electrochemical reactions; on the other hand, the substitutional doping of the graphene framework with heteroatoms (e.g., N or S) can tailor its electronic and chemical properties, and facilitate the uniform loading of high-density Pd nanoparticles. Moreover, the intrinsic activity of Pd/NSPGF is regulated by the interaction of Pd nanoparticles with the NSPGF support. Taking the advantages of morphology and composition, the self-supported Pd/NSPGF electrode displays remarkable electrochemical performance with a wide linear range up to 2.0 mM, low detection limit of 0.1 μM (S/N = 3), high sensitivity of 665 µA cm-2 mM-1, and good selectivity. When applied in real-time tracking of the H2O2 released from normal human colon epithelial cells and human colorectal cancer cells, the Pd/NSPGF-based electrochemical sensing system can distinguish the cell types by testing the number of extracellular H2O2 molecules released per cell, which holds considerable potential for early detection and monitoring of disease-related clinical specimens.© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.