School of Chemical Engineering and Pharmacy, School of Chemistry and Environmental Engineering, Key Laboratory of Novel Biomass-Based Environmental and Energy Materials in Petroleum and Chemical Industry, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Wuhan Institute of Technology, Hubei Province, China.
Pu Tuan Township Health Center, 31 FanPu Street, Ezhou, Hubei Province, 436030, China.
Anal Bioanal Chem. 2024 Dec;416(29):6995-7006. doi: 10.1007/s00216-024-05600-6. Epub 2024 Oct 21.
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 HO 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 mM, and good selectivity. When applied in real-time tracking of the HO 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 HO molecules released per cell, which holds considerable potential for early detection and monitoring of disease-related clinical specimens.
石墨烯薄膜因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一种很有前途的材料。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备的薄膜限制了其电催化性能。将活性金属物种或杂原子掺杂到石墨烯骨架中已被证明是提高基于石墨烯薄膜的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分布的 Pd 纳米粒子修饰的 N、S 共掺杂多孔石墨烯薄膜（Pd/NSPGF）组成的自支撑电极，并通过原位跟踪活细胞分泌的 HO 量来探索其在区分不同类型的人结肠细胞中的实际应用。我们的研究结果表明，一方面，NSPGF 具有丰富的表面和内部孔道，这促进了电化学过程中活性位点的暴露和质量扩散；另一方面，杂原子（如 N 或 S）取代掺杂到石墨烯骨架中可以调整其电子和化学性质，并有利于高密度 Pd 纳米粒子的均匀负载。此外，Pd/NSPGF 的本征活性受 Pd 纳米粒子与 NSPGF 载体之间相互作用的调节。该自支撑 Pd/NSPGF 电极具有独特的形貌和组成优势，表现出显著的电化学性能，线性范围宽达 2.0 mM，检测限低至 0.1 μM（S/N=3），灵敏度高达 665 µA cm mM，并且具有良好的选择性。当应用于实时跟踪正常人类结肠上皮细胞和人结直肠癌细胞释放的 HO 时，基于 Pd/NSPGF 的电化学传感系统可以通过测试每个细胞释放的细胞外 HO 分子数量来区分细胞类型，这对于疾病相关临床标本的早期检测和监测具有很大的潜力。
