A Direct Glimpse of Cross‐Hybridization: Background‐Passified Microarrays That Allow Mass‐Spectrometric Detection of Captured Oligonucleotides

Oligonucleotides immobilized in SAMs (self-assembled monolayers) with a passifying surface layer, prepared from thermally smoothed gold surfaces and disulfides, allow the direct detection of bound strands by MALDI-TOF mass spectrometry. The binding of perfectly matched (PM) and mismatched (MM) DNA targets is observed (see picture). The extent to which cross-hybridization occurs depends on the type and position of the mismatch.