Stable zinc metal-organic framework as efficient bifunctional fluorescent probe for selective detection of nitrobenzene and Fe(Ⅲ)

Through a solvothermal approach, a new zinc metal-organic framework (Zn-MOF), [Zn(PBA)(pic)(H2O)]·H2O·0.5DMA has been successfully engineered, based on 2-picolinic acid (Hpic) and 4-(pyridin-4-yl) benzoic acid (HPBA) ligands. We investigated the crystalline structure, chemical and thermal stability, and fluorescence properties by some modern techniques in detail. Zn-MOF possesses splendid water stability. Especially, the Zn-MOF displays remarkable fluorescent quenching effect toward nitrobenzene (NB) and Fe3+ ion. The high sensitivities KSV values for NB and Fe3+ are 3.80 ​× ​103 ​M−1, and 2.42 ​× ​104 ​M−1, and the low limit of detection values of NB and Fe3+ are 1.84 ​× ​10−5 ​M and 0.315 ​μM. Moreover, the electron and energy transfer mechanism are reasonably explained for the sensing mechanisms. As a result, Zn-MOF can be used as a dual-responsive luminescence quenching detector to detect NB and Fe3+ with outstanding sensitivity, selectivity and recyclability.