The Fe₂O₃ nanozyme has been identified as the most promising alternative for the Fe₃O₄ nanozyme due to its relatively low toxic risk and good chemical stability. However, its enzyme-like activity is relatively low enough to meet specific application requirements. Furthermore, previous synthesis approaches have difficulties in fabricating ultra-small Fe₂O₃ nanoparticles with tunable size and suffer from agglomeration problems. In this study, atomic layer deposition (ALD) was used to deposit Fe₂O₃ on surfaces of carbon nanotubes to form hybrid nanozymes (Fe₂O₃/CNTs). ALD enables the preparation of ultrafine Fe₂O₃ nanoparticles with precise size control <1 nm, while CNTs could be served as promising support for good dispersibility and as an effective activity activator. Hence, the formed Fe₂O₃/CNTs exhibit excellent peroxidase-like activity with a specific peroxidase activity of 24.5 U mg⁻¹. A colorimetric method for sensing dopamine (DA) was established and presented good sensitivity with a limit of detection (LOD) as low as 0.11 μM. These results demonstrated that, in virtue of meticulous engineering methods like ALD, carbon nanomaterial-based hybrids can be developed as talented enzyme mimetic, thus paving a way for nanozyme design with desired activity and broadening their applications in biosensing and other fields.

Fe ₂ O ₃纳米酶因其相对较低的毒性风险和良好的化学稳定性而被认为是Fe ₃ O ₄纳米酶最有前途的替代品。然而，其类酶活性相对较低，不足以满足特定的应用要求。此外，以前的合成方法难以制备尺寸可调的超小Fe ₂ O ₃纳米粒子，并且存在团聚问题。在本研究中，采用原子层沉积（ALD）将Fe ₂ O ₃沉积在碳纳米管表面，形成杂化纳米酶（Fe ₂ O ₃ /CNT）。 ALD能够制备具有精确尺寸控制的超细Fe ₂ O ₃纳米粒子<1 id=47>2 O ₃ /CNT表现出优异的类过氧化物酶活性，其比过氧化物酶活性为24.5 U mg ^-1 。建立了检测多巴胺（DA）的比色方法，该方法具有良好的灵敏度，检测限（LOD）低至0.11 μM。这些结果表明，凭借ALD等精细的工程方法，基于碳纳米材料的杂化物可以被开发为优秀的酶模拟物，从而为具有所需活性的纳米酶设计铺平了道路，并拓宽了其在生物传感和其他领域的应用。