Immobilization of Nucleic Acids at Solid Surfaces: Effect of Oligonucleotide Length on Layer Assembly
A B. Steel, R Levicky, T M. Herne, Michael J. Tarlov
This report investigates the effect of DNA length and the presence of an anchoring group on the assembly of pre-synthesized oligonucleotides at a gold surface. The work seeks to advance fundamental insight into issues that impact the structure and behavior of surface-immobilized DNA layers; for instance, as in DNA microarray and biosensor devices. The present study contrasts immobilization of single-stranded DNA (ssDNA)derivatized with a terminal, 5' hexanethiol anchoring group with that of unfunctionalized oligonucleotides for lengths from 8 to 48 bases. Qualitatively, the results indicate that the thiol anchoring group strongly enhances oligonucleotide immobilization but that the enhancement is reduced for longer strand lengths. Interestingly, examination of the probe coverage as a function of strand length suggests that adsorbed thiol-ssDNA oligonucleotides shorter than 24 bases tend to organize in end-tethered, highly extended configurations for which the long-term surface coverage is largely independent of oligonucleotide length. For strands longer than 24' bases, the surface covergage begins to decrease notably with probe length. The decrease is consistent with a less ordered arrangement of the DNA chains. presumably reflecting increasingly polymeric behavior.
, Levicky, R.
, Herne, T.
and Tarlov, M.
Immobilization of Nucleic Acids at Solid Surfaces: Effect of Oligonucleotide Length on Layer Assembly, Biophysical Journal
(Accessed June 8, 2023)