Mixed functionalization strategy on indium-organic framework for multiple ion detection and H2O2 turn-on sensing

Abstract

A special functional group mediated functionalization platform is introduced as a new and versatile platform tool to improve the fluorescence detection performance of metal–organic frameworks (MOF). The creation of a mixed-functionalization strategy on a MOF realizes the high sensitivity detection of heavy metal ions, anions and small molecules. In this work, we have first reported a novel amino functionalized 3D indium MOF [In(BDC-NH₂)(OH)]_n (In1-NH₂) which not only has an excellent fluorescent characteristic but also shows highly sensitive identification of Fe³⁺, Cu²⁺, Pb²⁺ and ClO⁻ in water with broad linear ranges and short response times. Subsequently, based on the remaining amino group site of In1-NH₂, a post-synthetic modification strategy is utilized to introduce an active boronic acid group for hydrogen peroxide detection. The obtained PBA-In1 exhibits an efficient sensing performance for hydrogen peroxide with an LOD of 0.42 μM. Given this, PBA-In1 is expected to become an effective probe to monitor the formation of metabolites in humans. In1-NH₂ successfully achieves multiple ion detection and the PBA-In1 sensing platform with boronic acid functionalization may have good application prospects in biochemical research in the future.