Electrochemical detection of single nucleotide polymorphism using gold electrode arrays modified with thiol linkers synthesized by solid-phase strategy

We developed an electrochemical DNA sensor based on gold electrode arrays modified with a thiol linker synthesized by novel solid-phase strategy, and could effectively detect the aging-dependant T414G mutation of mitochondrial DNA. To electrochemically detect the single nucleotide polymorphism (SNP), the gold electrode arrays were patterned on glass wafers, and the thiol linker facilely synthesized on the solid support was assembled on the gold electrode surface. On the SAM electrode surface, three kinds of DNA probes, T414G-T probe, T414G-G probe and control R probe, were covalently immobilized. Using the cyclic voltametry (CV), we could not only discriminate between full-matched DNA and single-mismatched DNA successfully, but also confirm the effectiveness of the synthesized thiol linkers for reducing the nonspecific DNA binding.