A boric acid-functionalized lanthanide metal-organic gel: A ratiometric fluorescence probe with rapid and sensitive detection of dopamine

In this study, a new ratio fluorescent gel probe based on boronic acid-modified BA-Tb-MOG was constructed and successfully applied to the analysis and detection of dopamine (DA). The dual emission BA-Tb-MOG probe sensing is realized by adjusting the energy conversion efficiency of the boronic acid-based ligand and Tb3+ ions. The 5-boronobezene-1, 3-dicarboxylic acid (DBA) organic ligand not only acted as the “antenna” to sensitize the luminescence of Tb3+ but also provided recognition sites for DA molecules. Dual fluorescence emission is generated at 325 nm and 545 nm under the excitation of 295 nm. The nucleophilic covalent binding of the boronic acid group to the cis-diol structure molecule provides a good basis for the specific and highly sensitive detection of DA. Owing to the porous characteristics and the surface effect of the MOF, as well as the unique nucleophilic reaction between the boronic acid group and DA, the novel gel nanoprobe exhibited outstanding characteristics for detection of DA, such as such as simple preparation, fluorescence stabilization, high sensitivity, and selectivity. It has been successfully applied to the detection of DA in human serum samples. This ratio fluorescence detection strategy provides an alternative sensing method for the rapid and sensitive analysis and determination of dopamine in complex biological samples.