Highly intensive and long-lasting chemiluminescence “Three-in-One” Hemin/Fe3O4@MoS2 hybrid nanozyme powered lab-on-fiber device for Ochratoxin A immunoassay

Abstract

A novel long-lasting chemiluminescent (CL) “Three-in-One” Hemin/Fe3O4 @MoS2 hybrid nanozyme powered lab-on-fiber (CN-LOF) device was developed for Ochratoxin A (OTA) detection. The “Three-in-One” nanozymes could catalyze luminol-H2O2 system to produce robust and long-lasting CL under pH range of 6.5–9.0 and temperature range of 0–70 ℃, such excellent catalytic activity was mainly originated from the synergistic effect of MoS2, Fe3O4 and hemin and the nanozyme’s elegant 2D/3D structure. In the reaction system, the nanozymes could continuously catalyze H2O2 to generate O2•− and 1O2 species, which was the main reason for the production of persistent CL. Using OTA antibodies labeled nanozyme for CL signal amplification while a reusable functionalized optical fiber as a biorecognition and separation element and also as a CL transducer, the CN-LOF could quantify OTA with high sensitivity and stability within 20 min. The obtained linear detection range for OTA was 0.69–65.85 ng/mL and the LOD was 0.16 ng/mL under optimal conditions. The proposed CN-LOF method had been successfully applied to the detection of OTA in underground water and milk samples, and the detection results were highly consistent with those of LC-MS, demonstrated the CN-LOF method had great application potential in the analysis of environmental samples and the detection of foodborne biotoxins.