An electrochemical biosensor based on CuFe PBA/MoS2 nanocomposites for stable and sensitive detection of hydrogen peroxide and carcinoembryonic antigen

An increasing number of electrochemical biosensors have been constructed to detect single bioactive substances with high sensitivity, but not multiple bioactive substances with different properties. Therefore, we incorporated Cu and Fe elements into Prussian blue to form Prussian blue analogues (PBA) to improve the electrochemical catalytic activity of Prussian blue. At the same time, MoS₂ is used as the material substrate to increase the electrochemical active site of the composite. We have constructed a universal electrochemical sensing platform using composite materials (CuFe PBA/MoS₂) as electrode modification materials for detecting two different types of representative cancer biomarkers, hydrogen peroxide (H₂O₂) and carcinoembryonic antigen (CEA). The universal electrochemical biosensor showed a significant linear response to both H₂O₂ and CEA with the lowest detection limits of 0.23 μM and 0.01 ng mL⁻¹, respectively, and it had high selectivity, reproducibility, and stability. The universal electrochemical biosensor is successfully applied to detect H₂O₂ released from human breast cancer (MCF-7) cells and CEA expressed on the surface of human cervical cancer (HeLa) cells. The developed biosensor has potential in the dynamic detection of the flux of H₂O₂ and the expression level of CEA from living cells. The high sensitivity of this universal sensor provides a novel strategy for simultaneously detecting multiple cancer biomarkers.