A new multifunctional anionic 3D Zn(ii)-MOF based on heptanuclear clusters: selective adsorption of organic dyes and a dual-emitting sensor for nitroantibiotics

A multifunctional anionic Zn-MOF, formulated as {[NH2(CH3)(2)][Zn-7(mu(3)-OH)(3)(L)(6)(H2O)]center dot 24H(2)O center dot 6DMA}(n) (1) (where H2L = 6-methoxy-2,2'-sulfone-4,4'-dicarboxylic acid and DMA = dimethylacetamide) has been solvothermally synthesized, which is based on rare heptanuclear [Zn-7(mu(3)-OH)(3)(COO)(12)] clusters possessing large 3D intersecting channels. Through a cation-exchange process, 1 can selectively adsorb cationic organic dyes, and the adsorption capacities for methylene blue (MB), rhodamine B (RhB) and crystal violet (CV) are 219.9, 114.6 and 197.6 mg g(-1), respectively. Moreover, the obtained RhB@1 composite features dual-emissive characteristics and can serve as a dual-channel sensor for selective sensing of traces of NF antibiotics (NFT and NFZ), with detection limits of 0.89 mu M and 0.95 mu M, respectively. The mechanism study shows that the quenching process is mainly ascribed to the synthetic effect of IFE and FRET.