Electrochemical methods with tissue-implantable microelectrodes provide an excellent platform for real-time monitoring the neurochemical dynamics in vivo due to their superior spatiotemporal resolution and high selectivity and sensitivity. Nevertheless, electrode implantation inevitably damages the brain tissue, upregulates reactive oxygen species level, and triggers neuroinflammatory response, resulting in unreliable quantification of neurochemical events. Herein, we report a multifunctional sensing platform for inflammation-free in vivo analysis with atomic-level engineered Fe single-atom catalyst that functions as both single-atom nanozyme with antioxidative activity and electrode material for dopamine oxidation. Through high-temperature pyrolysis and catalytic performance screening, we fabricate a series of Fe single-atom nanozymes with different coordination configurations and find that the Fe single-atom nanozyme with FeN₄ exhibits the highest activity toward mimicking catalase and superoxide dismutase as well as eliminating hydroxyl radical, while also featuring high electrode reactivity toward dopamine oxidation. These dual functions endow the single-atom nanozyme-based sensor with anti-inflammatory capabilities, enabling accurate dopamine sensing in living male rat brain. This study provides an avenue for designing inflammation-free electrochemical sensing platforms with atomic-precision engineered single-atom catalysts.

使用组织植入微电极的电化学方法由于其优越的时空分辨率以及高选择性和灵敏度，为实时监测体内神经化学动力学提供了一个极好的平台。然而，电极植入不可避免地会损伤脑组织，上调活性氧水平，并引发神经炎症反应，导致神经化学事件的量化不可靠。在此，我们报告了一种用于无炎症体内分析的多功能传感平台，采用原子级工程化的铁单原子催化剂，该催化剂既充当具有抗氧化活性的单原子纳米酶，又充当多巴胺氧化的电极材料。通过高温热解和催化性能筛选，我们制备了一系列具有不同配位构型的Fe单原子纳米酶，发现具有FeN ₄的Fe单原子纳米酶对模拟过氧化氢酶和超氧化物歧化酶以及消除羟基自由基，同时还具有对多巴胺氧化的高电极反应性。这些双重功能赋予基于单原子纳米酶的传感器具有抗炎能力，从而能够在活体雄性大鼠大脑中实现准确的多巴胺传感。这项研究为设计具有原子精度工程单原子催化剂的无炎症电化学传感平台提供了途径。