Construction and application of an electrochemical sensor based on MIL-101-NH2(Fe)-derived Fe–C porous materials doped with reduced graphene oxide for baicalin detection

Baicalin (Bn), a natural flavonoid compound, possesses high pharmacological effects. Here, an electrochemical sensor has been proposed based on an MIL-101-NH₂(Fe)-derived Fe porous carbon composite (Fe–C) doped with reduced graphene oxide (rGO) for detecting Bn, designated as Fe–C/rGO. Fabricated through a straightforward physical doping process, Fe–C/rGO exhibits remarkable electrochemical activity. This superiority stems primarily from two key factors. Firstly, the porous structure of Fe–C efficiently concentrates Bn, facilitating its capture and recognition. Secondly, graphene oxide, serving as a substrate for anchoring metal–organic frameworks (MOFs), boosts the electrochemical performance of the composite due to its distinctive two-dimensional structure, abundant active sites, and unparalleled stability. The synergistic interaction between Fe–C and rGO maximizes their respective advantages, leading to a significant enhancement in the sensitivity and selectivity of the electrochemical sensor. Boasting a low detection limit of 7.5 nM and a broad detection range spanning from 30 to 180 nM, this sensor holds immense potential in clinical applications and drug monitoring, offering a reliable and efficient method for Bn detection.