Leveraging Strong Interfacial Interactions between MoS₂ Nanoflowers and 3D Porous Carbon Networks for Enhancing Biomolecule Catalysis and Discrimination

Electroactive biomolecules, dopamine (DA) and uric acid (UA), as important biomarkers, often coexist in biological matrices. Due to their similar oxidation potentials, designing electrooxidation catalysts to efficiently detect and distinguish them and establishing structure-activity relationships remain a great bottleneck in the field of electrochemical sensing. Herein, an electrochemical sensor is designed by leveraging molybdenum disulfide nanoflowers embedded within 3D nitrogen-doped porous carbon networks (MoS₂@N-3DPC) for sensitive detection and discrimination of DA and UA. In constructing a heterogeneous interface between MoS₂ nanoflowers and N-3DPC, the incorporation of N-3DPC not only addresses the stacking issue but also markedly enhances the electrical conductivity. Moreover, the synthesis of petal-like MoS₂ shortens the electron and ion transfer pathways. The strong interfacial interaction between N-3DPC and MoS₂ effectively enhances the electrocatalytic performance of MoS₂@N-3DPC, as demonstrated by electrochemical analysis. The sensor demonstrates wide linear detection ranges (from 0.01 to 989.95 µm for DA and from 0.6 to 1063.4 µm for UA), low limits of detection for DA (3.0 nm) and UA (200.0 nm), as well as high selectivity and stability. Furthermore, such a sensor can be applied to the detection of DA and UA in real biological serum samples, with the results highly correlated with the spectrophotometric method.