Optimizing the Toehold Strategy of On-Chip Nucleic Acid Hybridization Probe for the Discrimination of Single Nucleotide Polymorphism.

The synthetic DNA hybridization probe has proved its importance in biology and biotechnology. In this study, taking advantage of a novel analytical technique called dual polarization interferometry (DPI), the influence of the toehold strategy of on-chip DNA hybridization probe on the discrimination of single nucleotide polymorphism (SNP) was investigated. Through adjusting the toehold length, the toehold strategies of on-chip toehold exchange probe were thoroughly optimized. For the "6/5" probe, an optimal discrimination factor of 78% against the spurious target was achieved. Moreover, the ability of the on-chip probe in SNP discrimination was significantly enhanced compared to its pure solution counterpart. This simple and rapid detection method for SNP discrimination based on the on-chip toehold exchange probe will show great potential in disease diagnosis.