Electrochemiluminescence immunosensor based on novel heterostructured Fe-MIL-88@1T-MoS2 dual-nanozyme with high peroxidase-like activity for sensitive NT-proBNP detection

Abstract

In this work, efficient Fe-MIL-88@1T-MoS2 dual-nanozyme and hollow CeO2 mono-nanozyme were synthesized as coreaction accelerators to fabricate electrochemiluminescence (ECL) immunosensor for N-terminal pro-brain natriuretic peptides (NT-proBNP) detection. Firstly, the peroxidase-like activity of the proposed Fe-MIL-88@1T-MoS2 dual-nanozyme was superior to that of individual Fe-MIL-88 and MoS2, owing to the synergistic catalytic effect that caused by the heterostructure. Therefore, they could be utilized as ideal coreaction accelerator to boost H2O2 decomposition and then generate abundant reactive oxygen species which could promote electrical oxidation of ABEI and obtain high ECL signal. Secondly, the rough surface of Fe-MIL-88@1T-MoS2 facilitated the mass capture of luminescent materials of ABEI modified silver nanoparticles (Ag-ABEI), which could further enhance the ECL signal of immunosensor. Finally, the hollow CeO2 also exhibited excellent catalytic performance toward to H2O2 decomposition owing to the facile redox-active Ce3+/Ce4+ and abundant surface oxygen vacancies, resulting in the ECL signal of immunosensor further enhanced. Therefore, the ECL immunosensor based on Fe-MIL-88@1T-MoS2 and hollow CeO2 exhibited extremely strong ECL signal and realized the ultra-sensitive detection of NT-proBNP with the detection limit down to 0.21 fg mL-1. Consequently, the results demonstrated that the proposed strategy may afford efficient means for trace protein sensitive detection.