A switch-on fluorescence assay for bacterial β-lactamases with amyloid fibrils as fluorescence enhancer and visual tool

Lan Zou, Wing Lam Cheong, Wai Hong Chung, Yun Chung Leung, Kwok Yin Wong, Man Kin Wong, Pak Ho Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)


Herein is described the development of a novel switch-on fluorescence assay for detecting β-lactamases. The fluorescence assay comprises two components: solid beads coated with a β-lactam antibiotic, which is linked to an environment-sensitive fluorophore (dansylaminothiophenol, DTA), and amyloid fibrils of hen lysozyme (acting as fluorescence enhancer and visual tool). In the presence of the clinically significant TEM-1 β-lactamase, the DTA-antibiotic complex on the solid beads is hydrolyzed, thus releasing the DTA dye into solution. The DTA dye is only weakly fluorescent in solution but gives strong green fluorescence upon binding to lysozyme fibrils. These strongly fluorescent DTA-bound fibrils can be easily visualized by the naked eye upon illumination of the sample with a simple UV lamp. The fluorescence assay can detect TEM-1 at low concentration (0.01a nM). In contrast, no observable fluorescence appears when the fluorescence assay is performed on samples without the TEM-1 β-lactamase. Visualizing bacterial β-lactamases: A switch-on fluorescence assay is developed for detecting bacterial β-lactamases. This simple fluorescence assay allows samples with β-lactamases to be conveniently identified through visual observation using amyloid fibrils as a fluorescence enhancer and visual tool.
Original languageEnglish
Pages (from-to)13367-13371
Number of pages5
JournalChemistry - A European Journal
Issue number45
Publication statusPublished - 3 Dec 2010


  • amyloid fibrils
  • antibiotics
  • bacteria
  • fluorescence
  • sensors

ASJC Scopus subject areas

  • Chemistry(all)

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