Bifunctional MIL-53(Fe) with pyrophosphate-mediated peroxidase-like activity and oxidation-stimulated fluorescence switching for alkaline phosphatase detection

J Mater Chem B. 2019 Aug 7;7(31):4794-4800. doi: 10.1039/c9tb00951e.


Alkaline phosphatase (ALP) is extensively used as a clinical biomarker because of its close relevance with a variety of diseases. Thus, exploring reliable and practical methods for ALP analysis is of great significance. In the present work, we explored MIL-53(Fe) as a bifunctional platform with pyrophosphate (PPi)-mediated peroxidase-like activity and oxidation-stimulated fluorescence switching for ALP sensing. The proposed MIL-53(Fe) could exhibit favorable peroxidase-mimicking activity to catalytically decompose H2O2 to hydroxyl radicals, which had strong oxidizing ability to oxidize the terephthalic acid bridging ligand, resulting in the oxidation-stimulated turn-on fluorescence of MIL-53(Fe) itself. Due to the strong coordination interaction between PPi and Fe3+, the former with a relatively large molecular structure was able to inhibit the catalytic activity of MIL-53(Fe) via capping active Fe3+ sites, leading to the suppression of its self-fluorescence response. When ALP was present, it could hydrolyze the PPi inhibitor and restore the dual functions of MIL-53(Fe) to provide fluorescence again. With the above principle, highly sensitive and selective determination of ALP with a linear scope of 2-80 U L-1 and a detection limit down to 0.7 U L-1 was achieved. The MIL-53(Fe) was also demonstrated to be very reliable in measuring the target in human serum, indicating its great promise as an integrated tool for ALP detection in clinical practice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / blood*
  • Alkaline Phosphatase / chemistry
  • Biomarkers / blood
  • Catalysis
  • Colorimetry / methods
  • Diphosphates / chemistry*
  • Fluorescence
  • Humans
  • Hydrogen Peroxide / chemistry
  • Limit of Detection
  • Metal-Organic Frameworks / chemistry*
  • Oxidation-Reduction
  • Peroxidase / chemistry
  • Phthalic Acids / chemistry
  • Spectrometry, Fluorescence / methods


  • Biomarkers
  • Diphosphates
  • Metal-Organic Frameworks
  • Phthalic Acids
  • diphosphoric acid
  • terephthalic acid
  • Hydrogen Peroxide
  • Peroxidase
  • Alkaline Phosphatase