Isolated iron atoms anchored on MOF-derived hollow N-doped carbon for the detection of dopamine

Sensitive and selective determination of neurotransmitter dopamine (DA) holds great significance in clinical disease diagnosis. Constructing highly active electrocatalysts at low costs is a favorable strategy for sensitive electrochemical detection of DA. In this work, taking a template-aided method, single-atom iron supported on hollow N-doped carbon matrix (Fe SA/HNC) was successfully synthesized. After the morphology and component of the prepared catalysts were characterized in details, it was used to construct electrochemical sensor. Given the excellent catalytic activity of Fe SA and the porous spherical structure of HNC, under the optimal conditions, the Fe SA/HNC sensor exhibited superior sensing performance to DA in a wide concentration range from 1.0 to 1000 µM with a low detection limit of 0.32 µM, along with good stability, reproducibility, and repeatability. In addition, the Fe SA/HNC sensor was also adopted to the simultaneous detection of three common small biomolecules including DA, uric acid (UA) and ascorbic acid (AA). Lastly, the applicability of the sensor was also well-demonstrated by detecting DA in real samples of human serum, showing satisfactory recoveries.