Abstract: A method determining the presence or absence of a single nucleotide polymorphism at a SNP site in a nucleic acid target. Capture probes are designed, each of which has a different SNP base and a sequence of probe bases on each side of the SNP base. The probe bases are complementary to the corresponding target sequence adjacent to the SNP site. Each capture probe is immobilized on a different electrode having a non-conductive outer layer on a conductive working surface of a substrate. The extent of hybridization between each capture probe and the nucleic acid target is detected by detecting the oxidation-reduction reaction at each electrode, utilizing a transition metal complex. These differences in the oxidation rates at the different electrodes are used to determine whether the selected nucleic acid target has a single nucleotide polymorphism at the selected SNP site.

Abstract: An electrode for detecting interactions between members of a binding pair, which electrode has been modified by formation of a non-conductive self-assembled monolayer, and a method of detecting biomolecules, such as nucleic acids or other targets, including receptors, ligands, antigens or antibodies, utilizing such an electrode. When contacted with a target nucleic acid, an oligonucleotide probe coupled to the self-assembled monolayer reacts with the target nucleic acid form a hybridized nucleic acid on the modified electrode surface. The hybridized nucleic acid is reacted with a transition metal complex capable of oxidizing a preselected base in the hybridized nucleic acid in an oxidation-reduction reaction, the oxidation-reduction reaction is detected, and the presence or absence of the nucleic acid is determined from the detected oxidation-reduction reaction.

Abstract: A method of detecting binding interactions and target molecules, such as proteins, protein fragments, recombinant proteins, recombinant protein fragments, extracellular matrix proteins, ligands, carbohydrates, steroids, hormones, drugs, drug candidates, immunoglobulins and receptors of eukaryotic, prokaryotic or viral origin, by mediated electrochemistry using labels that react with transition metal mediator complexes in a detectable catalytic redox reaction. These labels are attached directly to binders, target molecules, surrogate target molecules, or to affinity ligands capable of binding to the target or to surrogate target molecules capable of competing with the target for binding to another binder. The labels can be naturally present (endogenous) in the binder, target or affinity ligand, or constructed by the covalent attachment of the label to the binder, target, affinity ligand or surrogate target (exogenous).

Abstract: An electrode for detecting interactions between members of a binding pair, which electrode has been modified by formation of a non-conductive self-assembled monolayer, and a method of detecting biomolecules, such as nucleic acids or other targets, including receptors, ligands, antigens or antibodies, utilizing such an electrode. When contacted with a target nucleic acid, an oligonucleotide probe coupled to the self-assembled monolayer reacts with the target nucleic acid to form a hybridized nucleic acid on the modified electrode surface. The hybridized nucleic acid is reacted with a transition metal complex capable of oxidizing a preselected base in the hybridized nucleic acid in an oxidation-reduction reaction, the oxidation-reduction reaction is detected, and the presence or absence of the nucleic acid is determined from the detected oxidation-reduction reaction.

Abstract: A polymer-electrode including (a) a substrate having a conductive working surface; and (b) a polymer layer on the conductive working surface. The polymer layer has a plurality of microfluidic reaction openings distributed throughout the layer. An oligonucleotide probe can be attached to the polymer layer and is available to capture target nucleic acid. A soluble mediator can diffuse freely and transfer electrons from the preselected base in the hybridized nucleic acid to the conductive working surface of the substrate. An electronic signal generated from the electron transfer reaction is detected and quantitated.