SNPs feasibility of nonlabeled oligonucletides on using electrochemical sensing

We have demonstrated an electrochemical gene chip protocol for the SNPs detection of nonlabeled DNA. Using an array consisting of streptavidin-modified gold electrodes, probe DNA were attached through the application of a direct electric field. Electrochemical response changes originating from the hybridization of nucleic acids to protein-bound nucleic acids using soluble mediators in K3Fe(CN)(6) solution could then be observed. The electrochemical protocol developed showed high sensitivity and good reproducibility in the detection of DNA hybridization. Significant changes in electrochemical signals were also observed when using target DNA with a single base mismatch, indicating the applicability of this method to single nucleotide polymorphisms (SNPs) detection.