Fabrication and characterization of DNA arrays prepared on carbon-on-metal substrates.

Carbon-on-metal substrates consist of a surface plasmon-conducting metal substrate with a thin amorphous carbon overlayer. Recently, oligonucleotide arrays were in situ synthesized on carbon-on-gold substrates, and DNA hybridization experiments were monitored with surface plasmon resonance (SPR) imaging. We describe here the thorough characterization of these substrates and arrays as they progress through the fabrication process. Two surface plasmon-conducting metals, gold and silver, were utilized in the carbon-on-metal substrate preparation and their SPR responses compared. Oligonucleotide arrays synthesized on the carbon-on-metal substrates were analyzed with fluorescence- and SPR-based measurements. The stability of the carbon-on-metal substrates when exposed to prolonged incubations and/or serial hybridizations was also determined.