Liposome-based chemical barcodes for single molecule DNA detection using imaging mass spectrometry

Nano Lett. 2010 Feb 10;10(2):732-7. doi: 10.1021/nl904208y.

Abstract

We report on a mass-spectrometry (time-of-flight secondary ion mass spectrometry, TOF-SIMS) based method for multiplexed DNA detection utilizing a random array, where the lipid composition of small unilamellar liposomes act as chemical barcodes to identify unique DNA target sequences down to the single molecule level. In a sandwich format, suspended target-DNA to be detected mediates the binding of capture-DNA modified liposomes to surface-immobilized probe-DNA. With the lipid composition of each liposome encoding a unique target-DNA sequence, TOF-SIMS analysis was used to determine the chemical fingerprint of the bound liposomes. Using high-resolution TOF-SIMS imaging, providing sub-200 nm spatial resolution, single DNA targets could be detected and identified via the chemical fingerprint of individual liposomes. The results also demonstrate the capability of TOF-SIMS to provide multiplexed detection of DNA targets on substrate areas in the micrometer range. Together with a high multiplexing capacity, this makes the concept an interesting alternative to existing barcode concepts based on fluorescence, Raman, or graphical codes for small-scale bioanalysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DNA / chemistry*
  • Electronic Data Processing*
  • Fluorescence
  • Humans
  • Lipids / chemistry
  • Liposomes / chemistry*
  • Mass Spectrometry / methods*
  • Metal Nanoparticles / chemistry
  • Nanotechnology / methods*
  • Oligonucleotide Array Sequence Analysis / instrumentation*
  • Oligonucleotide Array Sequence Analysis / methods*

Substances

  • Lipids
  • Liposomes
  • DNA