Bimetallic PtCu nanoparticles supported on molybdenum disulfide–functionalized graphitic carbon nitride for the detection of carcinoembryonic antigen

A molybdenum disulfide based graphite phase carbon nitride (MoS₂/g-C₃N₄) which is supported by a platinum-copper nanoparticle (PtCu) Z-type catalyst was created in this study. The catalyst exploits optoelectronic synergistic effect with large surface area, good catalysis, and biocompatibility to amplify the signal. The electrode impedance of the synthesized MoS₂/g-C₃N₄-PtCu was reduced five times in visible light compared with dark conditions, thereby improving the detection of carcinoembryonic antigen (CEA). At a voltage of − 0.4 V, the immunoprobe constructed with this material is used for CEA detection. A linear relationship between 100 fg mL⁻¹ and 80 ng mL⁻¹ concentrations was achieved with a minimum detection limit of 33 fg mL⁻¹ (S/N = 3). The recovery rate was 103–104%, and the relative standard deviation was 2.9–3.8%. This implies that the sandwich immunosensors have good reproducibility, selectivity, and stability and can be used in various applications.