Ultrasmall metal-organic framework zn-mof-74 nanodots: Size-controlled synthesis and application for highly selective colorimetric sensing of iron(III) in Aqueous Solution

Jiuhai Wang, Yadi Fan, Hang Wei Lee, Changqing Yi, Changming Cheng, Xin Zhao, Mo Yang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

38 Citations (Scopus)


Here, a novel colorimetric sensing platform for highly selective detection of Fe3+ in aqueous solutions was developed based on zero-dimensional Zn-MOF-74 [Zn2(DOBDC), DOBDC = 2,5-dihydroxyterephthalic acid] nanodots. The first ultrasmall Zn-MOF-74 nanodots with the average size within 10 nm were successfully synthesized by manipulating the initial conditions with a diluted material system. It was found that the ultrasamll MOF nanodots had a highly selective interaction with Fe3+ and showed a specific blue colorimetric change in aqueous solution. The highly dispersive nature in aqueous solution and high surface-to-volume ratio help MOF-74 nanodots closely interact with the targeted Fe3+ ions with a low limit of detection of 1.04 μM and a fast response within seconds. Finally, we demonstrate that the selective Fe3+ sensing mechanism of Zn-MOF-74 nanodots is due to the selective framework disruption and the formation of Fe-DOBDC salt complex with blue color. It is the first report of nanoscale MOF based colorimetric Fe3+ sensor with low limit of detection (LOD) comparable even to fluorescent MOF based Fe3+ sensors, which could be easily observed by naked-eye without expensive fluorescence apparatuses. The good colorimetric stability in aqueous environment, low limit of detection, rapid response, and nanosize nature enable this MOF nanodot to be a good Fe3+ sensing probe for biological and environmental sensing applications.

Original languageEnglish
Pages (from-to)3747-3753
Number of pages7
JournalACS Applied Nano Materials
Issue number7
Publication statusPublished - 27 Jul 2018


  • colorimetric sensing
  • metal ion detection
  • metal-organic framework
  • nanodot
  • zero-dimensional

ASJC Scopus subject areas

  • Materials Science(all)

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