Antibiotic contamination of water bodies is a major environmental concern. Exposure to superfluous antibiotics is an ecological stressor correlated to the development of antibiotic resistance. Thus, it is imperative that effective methods are developed to simultaneously detect and remove such antibiotics so as to avoid inadvertent release. Herein, two flexible three-dimensional (3D) zinc-based metal–organic frameworks (MOFs) {[Zn2(bcob)­(OH)­(H2O)]·DMA} n (ROD-Zn1) and {[Zn­(Hbcob)]·(solvent)} n (ROD-Zn2) (H3bcob = 1,3-bis­((4′-carboxylbenzyl)­oxy)­benzoic acid) with rod second building units (SBUs) are successfully prepared. Their exceptional water and chemical stabilities (toward both acid and base), fast sorption kinetics, and unique framework endow the MOFs with excellent uptake capacity toward various antibiotics in the aqueous environment. The adsorption performance was further optimized by one-pot preparation of MOF-melamine foam (MF) hybrid composites, resulting in a hierarchical microporous–macroporous MOF@MF system (ROD-Zn1@MF and ROD-Zn2@MF), which are readily recyclable after adsorptive capture. The mechanisms of adsorption have been deeply investigated by static and competitive adsorption experiments. In addition, the MOFs exhibit excellent fluorescent properties and quenched by trace amounts of antibiotics in water solution. Therefore, ROD-Zn1 and ROD-Zn2 present a dual-functional performance, being promising candidates for detection and removal of antibiotics.

Efficient turn-on luminescent probes for l-cysteine sensing in serum are designed and synthesized based on an anionic Ln–K–MOF with tunable emission color and heavy metal ion adsorption capacity.

A new simple 'dual' chemosensor MQA ((E)-2-methoxy-N-((quinolin-2-yl)methylene)aniline) for distinguishing Zn and Hg has been designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn/Hg over other commonly coexisting cations (such as Na, Mg, Al, K, Mn, Fe, Fe, Co, Ni, Cu, Ga, Cd, In and Pb) in DMSO-HO solution (1/99 v/v), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit for Zn/Hg by MQA both reached the 10 M level. The 1 : 1 ligand-to-metal coordination patterns of the MQA-Zn2+ and MQA-Hg2+ were calculated through a Job's plot and ESI-MS spectra, and were further confirmed by X-ray crystal structures of complexes MQA-Zn2+ and MQA-Hg2+. This chemosensor can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions. DFT calculations have revealed that the energy gap between the HOMO and LUMO of MQA has decreased upon coordination with Zn(ii)/Hg(ii).

Accurate hydrophobicity adjustment of single-phase material is quite challenging and meaningful for water treatment. Here, a strategy combining crystal morphology regulation and post-synthetic modification is reported based on a novel metal−organic framework (MOF, Eu-bdo-COOH, H 4 bdo = 2,5-bis(3,5dicarboxylphenyl)-1,3,4-oxadiazole). The hydrophobicity is regulated by crystal size and morphology regulation, and a rough microspherical MOF is successfully synthesized. Meanwhile, the obtained MOF microspheres exhibit high water, chemical, and thermal stability. The post-synthetic modification of alkyl chains achieves fine-tuning of hydrophobicity of MOF microspheres. The static water contact angles can controllably range from 43 to 142°, and the amylaminemodified MOF (AM) obtains the strongest hydrophobicity. In addition, a superhydrophobic aerogel is constructed with AM microspheres and reduced graphene oxide (rGO) for efficient oil−water separation. The AM-rGO aerogel (AM-rGA) exhibits fast and efficient absorption of various oily substances from water, and the adsorption capacity of dibromoethane reaches up to 14,728 wt %. This outstanding oil adsorption capacity can maintain even beyond 50 cycles by the support of the stable aerogel. The strategy of morphology regulation and post-synthetic modification provides a broad approach for the hydrophobic adjustment of numerous MOF materials.