Ionic strength-controlled hybridization and stability of hybrids of KRAS DNA single-nucleotides: A surface plasmon resonance study

Publication year: 2017
Authors: Giamblanco N. 1, Petralia S. 2, Conoci S. 3, Messineo C. 4, Marletta G. 4
Affiliations:

1 - Department of Chemical Sciences, University of Catania, Viale A. Doria 6 - 95129 Catania, Italy
2 - STMicroelectronics, Stradale Primosole 50, 95121 Catania, Italy
3 - STMicroelectronics, Stradale Primosole 50, 95121 Catania, Italy
4 - Department of Chemical Sciences, University of Catania, Viale A. Doria 6 - 95129 Catania, Italy

Published in: Colloids and Surfaces B: Biointerfaces, 2017, Vol. 158, p. 41-46
doi: 10.1016/j.colsurfb.2017.06.021

The discrimination of a fully matched, unlabeled KRAS wild-type (WT) (C-G) target sample with respect to three of the most frequent KRAS codon mutations (G12 S (C-A), G12 R (C-C), G12C (C-T)) was investigated using an optimized detection strategy involving surface plasmon resonance (SPR), based on optimized probe-surface density and ionic strength control. The changes observed in the SPR signal were always larger for WT compared with the single-mismatch target DNA oligonucleotides, and were aligned with the theoretical energy differences between the base pair C-G, C-T, C-A, C-C. Hybridization rates of ∼106M-1s-1 were detected without the introduction of high temperature and labels, usually needed in conventional hybridization methods. One hundred percent mutation discrimination of the matched KRAS wild-type (C-G) sequence with respect to three mismatched G12C (C-T), G12 S (C-A), G12 R (C-C) target sequences was achieved.


MP-SPR keywords: biosensor, cancer detection, comparing binding of target and most common mutations, detection of dna mutations, detection of target dna, DNA oligonucleotides, DNA-DNA interactions, hybridization efficiency, KRAS gene mutations, ssDNA probe binding on gold