Quantitative study of the effect of coverage on the hybridization efficiency of surface-bound DNA nanostructures.
We demonstrate that, contrary to current understanding, the density of probe molecules is not responsible for the lack of hybridization in high density single-stranded DNA (ss-DNA) self-assembled monolayers (SAMs). To this end, we use nanografting to fabricate well packed ss-DNA nanopatches within a "carpet matrix" SAM of inert thiols on gold surfaces. The DNA surface density is varied by changing the "writing" parameters, for example, tip speed, and number of scan lines. Since ss-DNA is 50 times more flexible than ds-DNA, hybridization leads to a transition to a "standing up" phase. Therefore, accurate height and compressibility measurements of the nanopatches before and after hybridization allow reliable, sensitive, and label-free detection of hybridization. Side-by-side comparison of self-assembled and nanografted DNA-monolayers shows that the latter, while denser than the former, display higher hybridization efficiencies.
ELETTRA, Sincrotrone Trieste S.C.p.A., S.S. 14 Km 163.5 Basovizza, 34012 Trieste, Italy.
Elham
E
Mirmomtaz
Matteo
M
Castronovo
Christian
C
Grunwald
Fouzia
F
Bano
Denis
D
Scaini
Ali A
AA
Ensafi
Giacinto
G
Scoles
Loredana
L
Casalis
D004247:DNA / Q000737:chemistry*; D049329:Nanostructures; D009693:Nucleic Acid Hybridization; D013499:Surface Properties
D004247:DNA