Fluorescent Mesoporous Nanoparticles for β-Lactamase Screening Assays

ChemistryOpen. 2020 Oct 23;9(10):1074-1081. doi: 10.1002/open.202000221. eCollection 2020 Oct.

Abstract

We present a sensitive and rapid screening method for the determination of β-lactamase activity of antibiotic-resistant bacteria, by designing a pH-sensitive fluorescent dye-doped mesoporous silica nanoparticle encapsulated with penicillin G as a substrate. When penicillin G was hydrolysed by β-lactamase and converted into penicilloic acid, the acidic environment resulted in fluorescence quenching of the dye. The dye-doped mesoporous nanoparticles not only enhanced the β-lactamase-catalyzed reaction rate but also stablized the substrate, penicillin G, which degrades into penicilloic acid in a water solution without β-lactamase. Twentyfive clinical bacterial samples were tested and the antibiotic resistant and susceptible strains were identified. The proposed method may detect the presence of β -lactamases of clinically relevant samples in less than 1 hour. Moreover, the detection limit of β-lactamase activity was as low as 7.8×10-4 U/mL, which was determined within two hours.

Keywords: antibiotic-resistant bacteria; dye-doped mesoporous nanoparticles; fluorescence spectroscopy; penicillin G; β-lactams.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocatalysis
  • Enzyme Assays / methods*
  • Fluorescent Dyes / chemistry*
  • Kinetics
  • Nanoparticles / chemistry*
  • Penicillin G / chemistry
  • Porosity
  • Time Factors
  • Water / chemistry
  • beta-Lactamases / chemistry
  • beta-Lactamases / metabolism*

Substances

  • Fluorescent Dyes
  • Water
  • beta-Lactamases
  • Penicillin G