Regular Article Kinetic discrimination of DNA single-base mutations by localized surface plasmon resonance Antonino Rapisarda, Nicoletta Giamblanco ⇑ , Giovanni Marletta Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemical Science, University of Catania and CSGI, Italy graphical abstract article info Article history: Received 17 August 2016 Revised 12 October 2016 Accepted 13 October 2016 Available online 14 October 2016 Keywords: Localized surface plasmon resonance DNA hybridization kinetic Single base mutation detection KRAS abstract Clinical application of DNA microarrays used for screening of single nucleotide polymorphisms (SNPs) are very important for diagnosis of diseases and appropriate treatment of patients. In this paper localized surface plasmon resonance (LSPR) technique has been used to study the DNA hybridization process for binary solutions of respectively perfectly matching (PM) and single base mismatching (MM) 93-mer ssDNA from KRAS codon 12. 5 0 -thiol modified 35-mer ssDNA has been linked to the Au nanodisks array as probe with a surface coverage of 2.8 ± 0.1  10 12 /cm 2 . Probe’s binding properties was investigated in details, obtaining a sensitivity down to 10 nM and 13 nM, respectively for PM and MM, showing that the hybridization process occurs at a lower rate for MM with respect to PM target. The competitive hybridiza- tion is accounted for by an inhibition model, where the non-complementary sequences kinetically hinder the hybridization of the perfect matching sequences, owing to their above mentioned affinity constant differences for the same probe. Accordingly, the single nucleotide polymorphisms can therefore be revealed in a single step and label free mode with high sensitivity and specificity by LSPR measurements. Ó 2016 Elsevier Inc. All rights reserved. 1. Introduction Single base polymorphisms (SNPs) are the most abundant and common form of genetic variation [1] and are prevalent in clinical issues [2]. For instance, point mutation in the Kirsten Rat Sarcoma viral oncogene homologous (KRAS) gene codon 12, 13, and 61 are associated with the development of certain pancreatic and lung cancers [3] and their detection is critical for the selection of the appropriate type of treatment [4]. Until today the most used technologies designed to reveal SNPs are based on the principle of allele-specific hybridization, relying http://dx.doi.org/10.1016/j.jcis.2016.10.026 0021-9797/Ó 2016 Elsevier Inc. All rights reserved. ⇑ Corresponding author. E-mail address: n.giamblanco@unict.it (N. Giamblanco). Journal of Colloid and Interface Science 487 (2017) 141–148 Contents lists available at ScienceDirect Journal of Colloid and Interface Science journal homepage: www.elsevier.com/locate/jcis