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A metal (Co)-Organic Framework (Co-MOF) was first found to catalyze the chemiluminescence (CL) of luminol. On the basis of X-ray photoelectron spectroscopy, powder X-ray diffraction, CL spectral, UV-visible absorption spectral, and electron spin resonance (ESR) spectral studies, as well as the research of the influence of various free radical scavengers, a possible CL mechanism was proposed. The enhanced CL might be attributed to the formation of a peroxide analogous complex between the oxygen-related radicals and the active metal site of the Co-MOF material. The established Co-MOF-luminol CL system was successfully applied to determine L-cysteine (CySH), based on the selective and sensitive enhancing effect of CySH on this CL system. Under the optimized conditions, CySH was selectively detected in the range 0.1-10 μM with a detection limit of 18 nM. This novel CL system obviously gives impetus to the new research field of metal-organic frameworks (MOFs) in chemiluminescence.

The present study outlines a one‐step route to the preparation and functionalization of graphene nanosheets from graphene oxide using tea polyphenols as a simultaneous reductant and functionalization reagent. This method uses a “green” reductant and is free of additional functionalization reagents, thus it is environmentally friendly, simple, and low‐cost. The resulting functionalized graphene nanosheets have a mostly single‐layer structure, are stable, and have very good water dispersibility. The structure, composition, and morphology of the resulting material were characterized by using various methods including, X‐ray diffraction (XRD), UV/Vis spectroscopy, Raman spectroscopy, detailed X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Among other possible applications of the functionalized graphene, we discuss its use as an adsorbent for heavy‐metal ions in aqueous solutions.

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