Fluorescence assay based on aptamer-quantum dot binding to Bacillus thuringiensis spores

J Fluoresc. 2007 Mar;17(2):193-9. doi: 10.1007/s10895-007-0158-4. Epub 2007 Jan 31.

Abstract

A novel assay was developed for the detection of Bacillus thuringiensis (BT) spores. The assay is based on the fluorescence observed after binding an aptamer-quantum dot conjugate to BT spores. The in vitro selection and amplification technique called SELEX (Systematic Evolution of Ligands by EXponential enrichment) was used in order to identify the DNA aptamer sequence specific for BT. The 60 base aptamer was then coupled to fluorescent zinc sulfide-capped, cadmium selenide quantum dots (QD). The assay is semi-quantitative, specific and can detect BT at concentrations of about 1,000 colony forming units/ml.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Nucleotide / chemical synthesis
  • Aptamers, Nucleotide / chemistry*
  • Bacillus thuringiensis / chemistry
  • Bacillus thuringiensis / genetics
  • Bacillus thuringiensis / isolation & purification*
  • Cadmium Compounds / chemistry
  • Colony Count, Microbial / methods*
  • Fluorescence
  • Quantum Dots*
  • Selenium Compounds / chemistry
  • Spectrometry, Fluorescence / methods*
  • Spores, Bacterial / chemistry
  • Spores, Bacterial / genetics
  • Spores, Bacterial / isolation & purification
  • Sulfides / chemistry
  • Zinc Compounds / chemistry

Substances

  • Aptamers, Nucleotide
  • Cadmium Compounds
  • Selenium Compounds
  • Sulfides
  • Zinc Compounds
  • cadmium selenide
  • zinc sulfide