Liposome-Based Chemical Barcodes for Single Molecule DNA Detection Using Imaging Mass Spectrometry

• 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.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

nanoparticle probes

liposome

barcode

high-density

maldi-tof

expression

TOF-SIMS

targets

DNA

sims

arrays

hybridization

single molecule detection

Publication and Content Type

art (subject category)

ref (subject category)