Nanoscaled luminescent terbium metal-organic frameworks for measuring and scavenging reactive oxygen species in living cells

A luminescent terbium metal-organic framework (Tb-MOF) was prepared using Tb³⁺ as metal ions and a boronic acid ligand (3,5-dicarboxybenzeneboronic acid) as linkers, which was successfully employed for the detection and scavenging of reactive oxygen species (ROS) in living cells. After the formation of the Tb-MOF, the luminescence of Tb³⁺ is sensitized by the organic linkers. In addition, the functionalization of boronic acid groups in the channels of MOFs also enhances the luminescence of Tb³⁺ ions through the antenna effect by adjusting the energy level of the ligand. In addition, the free boronic acid groups act as active sites and react with ROS due to a rapid nucleophilic addition reaction, which leads to the luminescence quenching of Tb-MOF. On the basis of these findings, the boronic acid-functionalized Tb-MOF can be used as an excellent ROS scavenger and a nanoprobe for highly selective and sensitive detection of ROS in living cells.