A sandwich-configuration electrochemiluminescence immunoassay based on Cu2O@OMC-Ru nanocrystals and OMC-MoS2 nanocomposites for determination of alpha-fetoprotein

A sandwich-format electrochemiluminescence (ECL) immunosensor has been developed for alpha-fetoprotein (AFP) detection based on the use of ordered mesoporous carbon-molybdenum disulfide (OMC-MoS 2 ) as a sensor platform and cuprous oxide @ ordered mesoporous carbon-Ru(bpy) 3 2+ (Cu 2 O@OMC-Ru) composites as signal tags. OMC alongside MoS 2 plays a synergistic role in improving the electrochemical performance of the electrode in the electron transfer process. The uniform cubic-shaped Cu 2 O@OMC-Ru nanocrystals display excellent luminous efficiency, with a signal amplification strategy of OMC-MoS 2 synergistic enhancement and Cu 2 O@OMC which is capable of immobilizing more Ru(bpy) 3 2+ serving as a tracing tag to label antibodies. A detectable ECL emission at a Cu 2 O@OMC-Ru nanocrystals modified electrode is initiated at an applied voltage of +1.15 V (scanning range: 0–1.2 V), in the presence of the tripropylamine (TPA) as coreactant. With the increase in AFP concentration, the loading of Cu 2 O@OMC-Ru at the electrode increases. Afterward, the ECL detection of AFP shows a wide linear range from 0.1 pg/mL to 10 ng/mL with a correlation coefficient of 0.9964 and a detection limit of 0.011 pg/mL (S/ N = 3) under the optimal experimental conditions. The recoveries were in the range 91.2–97.1% with RSD varying from 4.8 to 8.5%. Overall, the novel immunosensor has been successfully applied to the analysis of human serum samples, indicating a great potential for application in clinical diagnostics. Graphical abstract