Development of a sensitive long-wavelength fluorogenic probe for nitroreductase: A new fluorimetric indictor for analyte determination by dehydrogenase-coupled biosensors

Hun Chung Huang, Kun Li Wang, Sheng Tung Huang, Hsin Yi Lin, Chun Mao Lin

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39 Citations (Scopus)


Nitroreductase (NTR) is a flavin-containing enzyme that uses NADH as the electron source to reduce nitroaromatic compounds to the corresponding amines. Previous studies have shown that nitroreductase-targeted latent fluorophores exhibit low solubility in the aqueous media and fluoresce at lower wavelengths upon uncloaking, thus limiting their effective applications. Here, we have prepared a new switch-on long-wavelength latent fluorogenic substrate, NTRLF (4), for NTR. In the presence of NADH, NTR catalyzes the reduction of the nitroaromatic moiety in NTRLF (4), followed by the cascade reaction, 1,6-rearrangement-elimination reaction, cyclic urea formation, and concomitant ejects a long-wavelength fluorescence coumarin (8). However, this reaction was inhibited in the presence of nitroaromatic analogues. The fluorescence signal generated by the cascade reaction was specific and insensitive to various reductants. Accordingly, we propose that NTRLF and NTR in the presences of NADH constitute a useful switch-off high-throughput fluorescence sensor for screening nitroaromatic compounds. Furthermore, NTRLF in the NTR-coupled 3-hydroxybutyrate dehydrogenase and aldehyde dehydrogenase assay reactions was a sensitive fluorimetric indicator for the quantitatively measurement of 3-hydroxybutyrate and propionaldehyde, respectively within micromolar range. Our novel NTRLF and NTR-coupled dehydrogenase assay platform may thus be effectively applied for the quantitative estimation of a broad range of analytes.

Original languageEnglish
Pages (from-to)3511-3516
Number of pages6
JournalBiosensors and Bioelectronics
Issue number8
Publication statusPublished - Apr 15 2011



  • 3-Hydroxybutyrate
  • Aldehyde
  • Latent fluorogenic substrate
  • Nitroaromatic compounds
  • Nitroreductase

ASJC Scopus subject areas

  • Biophysics
  • Biomedical Engineering
  • Biotechnology
  • Electrochemistry

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