A High Selective and Sensitive Cr2O72−sensing by a Reusable Cu-based metal-organic Framework

The utilization of metal-organic frameworks (MOFs) as luminescent sensors towards specific ions or molecular sensing has garnered significant attention, owing to their porous and easy-decorated feature. Herein, a Cu-based MOF (noted as SQ-1) has been synthesized using 5-amino-isophthalic acid as a bridging ligand. The SQ-1 was structurally characterized and demonstrated good thermal and water stability. Additionally, the benign luminescent properties of the ligands suggest its potential application as a luminescent sensor for detecting various anions. Notably, SQ-1 exhibited a remarkable selective and sensitive sensing ability towards Cr₂O₇²⁻ compared to other anions via luminescence quenching response, with the K_sv of 3.98 × 10⁴ M⁻¹ and detection limit of 4.32 µM. The quenching mechanism has been explored. Furthermore, this Cu-based MOF shows promise as a reusable luminescent sensor, maintaining functionality over three consecutive sensing cycles.