Stress and DNA assembly differences on cantilevers gold coated by resistive and e-beam evaporation techniques.
Changes in the sign of differential surface stress of gold-coated cantilevers produced by thiol-derivatized single-stranded DNA immobilization are observed, depending on the method used to deposit the gold. While the DNA immobilization on e-beam gold-coated cantilevers produces a compressive differential surface stress in the metallic layer, the opposite is observed for resistively coated cantilevers under the same immobilization conditions. The gold films exhibit quite a similar morphology, and the immobilization differences seem to be related to the charge state of the metallic layer surface. This in turn produces a different distribution of the orientation of the DNA strands on the gold layer. A tentative explanation for the observed effect is proposed.
Arroyo-Hernández
M
M
Instituto de Microelectrónica de Madrid, IMM-CNM-CSIC, Isaac Newton 8, PTM, 28760 Tres Cantos, Madrid, Spain. marroyo@imm.cnm.csic.es
Tamayo
J
J
Costa-Krämer
J L
JL
D001483:Base Sequence; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000235:genetics; D006046:Gold / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D013314:Stress, Mechanical; D013438:Sulfhydryl Compounds; D014835:Volatilization
D004277:DNA, Single-Stranded; D013438:Sulfhydryl Compounds; D006046:Gold