Novel cobalt-based metal-organic frameworks with superior catalytic performance on N-(4-aminobutyl)-N-ethylisoluminol chemiluminescent reaction

Highlights: • Novel Co MOFs were synthesized by a facile "controlled synthesis" strategy. • The Co-MOFs displayed superior catalytic performance on chemiluminescent reaction. • The catalytic activity was attributed to generation of large amounts of reactive oxygen species. • A highly sensitive immunoassay method was established by using Co MOFs to enhance chemiluminescent signal. Novel cobalt-based metal-organic frameworks (Co MOFs) were synthesized by a facile "controlled synthesis" strategy. The MOFs displayed superior catalytic performance on the chemiluminescent (CL) reaction between N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and H₂O₂. UV–vis absorption, CL spectrum, ESR, and radical scavenger experiments were conducted for clarifying the catalytic mechanism of Co MOFs. All results revealed that Co MOFs can accelerate decomposition of H₂O₂ and production of OH^• , O₂^{• −}as well as ¹O₂ radicals. The rapid reaction between these reactive oxygen species and ABEI resulted in the generation of ABEI-ox∗. The excited-state oxidation product emitted a very intensive CL signal with a maximal emission wavelength of 430 nm as it returned to the ground state. To explore their application potential in CL assay, Co MOFs were used as powerful CL reaction catalyst for establishing a very sensitive method for immunoassay of aflatoxin B₁. The detection range was 0.05–60 ng mL⁻¹, and the limit of detection was 4.3 pg mL⁻¹. The result for detecting herbal medicine samples demonstrates the acceptable reliability of the Co MOFs-based CL immunoassay. The proof-of-principle work verifies the application potential of Co MOFs on boosting intensive CL signal, and meets the demand for high sensitivity in various bioassay fields.