Design of oligonucleotide arrays at interfaces

The surface attachment and detection of DNA probes are essential in the des ign of nucleic acid-based biosensors. A new strategy for the covalent immob ilization of single-stranded oligonucleotides on gold-covered planar suppor ts is presented. Optimization of the surface density in the resulting DNA a rrays permits a high hybridization efficiency to be achieved. Surface plasm on resonance and, for the first time, ATR-FTIR spectroscopy are used to fol low in situ the oligonucleotide layer formation and the subsequent compleme ntary strand hybridization. Such well-defined, covalently immobilized oligo nucleotide arrays can find application in the development of novel DNA-base d sensors for mutation detection and gene mapping as well as in studies of nucleic acid-ligand interactions.