Co, Fe Dual-Doped MoS₂ Nanosheets on Polypyrrole Microtubes as Effective Peroxidase Mimics for Glutathione Sensing

Heteroatom doping is considered an effective way to enhance the catalytic activity of MoS₂ nanosheets (NSs). In the paper, dual-metal doping was proposed to incorporate Fe and Co into hierarchical MoS₂ ultrathin NSs, which grew directly on polypyrrole microtubes (Fe, Co-MoS₂@PPy), for the enhanced enzyme-like catalytic reaction. The particular hollow tubular structure realized effective electron transfer. The doped Fe and Co tuned the electronic architecture of the MoS₂ NSs to enhance the enzyme-like catalytic activity. The abundant exposed void spaces facilitated ion diffusion/penetration between the PPy interlayer and Fe-Co doped MoS₂ shell, leading to heterostructured synergistic effects. Therefore, the synthesized Fe and Co-MoS₂@PPy composites showed remarkable catalytic activity. The high catalytic efficiency of Fe and Co-MoS₂@PPy was confirmed with the reaction of tetramethylbenzidine (TMB) and H₂O₂ for visible detection. The blue color disappeared after adding glutathione (GSH). Thus, this procedure was used as a convenient way to detect GSH with a detection limit of 0.76 μM. The dual-metal-doped strategy was confirmed to improve the performance of MoS₂ nanocomposites and could be used as a promising matrix for other applications, such as electrochemical energy conversion, medical diagnosis, and others.