Encapsulation of luminol and Co2+ within a metal–organic framework for enhanced chemiluminescence and imaging of inflammation

Abstract

Chemiluminescence can eliminate interference caused by excitation light sources, thereby providing ultrasensitive imaging for the detection of various diseases. In this work, we report a novel chemiluminescent system by encapsulating luminol and Co²⁺ within a metal–organic framework (MOF) UiO-67-bpydc. Due to the chelation of the Co²⁺ on the N-site from the ligand as well as the confinement of luminol within the pores of UiO-67-bpydc, the synthesized MOF composite UiO-67-bpydc⊃Co+Lu exhibits significantly enhanced chemiluminescence intensity, which is 8300 times higher than that of luminol. The potential practical application of UiO-67-bpydc⊃Co+Lu was also evaluated by the quantitative analysis of H₂O₂ and glucose. The results indicate that the H₂O₂ and glucose could be linearly detected over the range from 10 to 100 μM with a detection limit of 0.52 μM and 10 to 400 of μM with a detection limit of 1.36 μM, respectively. By taking advantage of the sensitive sensing properties and excellent biocompatibility, chemiluminescence imaging of skin inflammation in mice was demonstrated utilizing UiO-67-bpydc⊃Co+Lu. This work provides inspiration to design highly emissive chemiluminescent materials for use in diagnosis.