Imaging TOF-SIMS analysis of oligonucleotide microarrays

Single strand thiolated oligonucleotide (25-mer) was printed onto chemically modified glass and silicon surfaces. Confirmation of the level of attachment attained in each case was effected through detection by conventional confocal fluorescence microscopy. Both positive-ion and negative ion imaging time-of-flight mass spectra were recorded for the visualization of micro-patterned oligonucleotide arrays. This represents the first report of such detection by this form of mass spectrometry on glass. Ultimately, we are interested in the possibility that imaging time-of-flight secondary ion mass spectrometry can discern the orientation and conformation of DNA strands present on the surface of a substrate.