Compositions and methods for detecting redox-active molecules in solution
OwnerStephen E. Creager, Marla French +1inventors
InventorsStephen E. Creager, Marla French, Philip T. Radford
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Abstract
An electrochemical amplification scheme for detecting very small amounts of redox-active molecules is disclosed. The reaction involves “recycling” of oxidized analyte molecules by way of a solution-phase electron exchange reaction with a sacrificial electron donor. The scheme relies heavily upon the action of a selective monolayer coating on the electrode that suppresses direct oxidation of the sacrificial donor but facilitates the oxidation of analyte molecules. The method is particularly useful for detection of hydroxymethylferrocene at a dodecanethiolate-coated gold electrode with ferrocyanide as the sacrificial electron donor.
Claims21
A method of detecting an analyte in solution, comprising:
- (a) providing a solution having an analyte therein;
- (b) providing an electrode in electrical communication with the solution;
- (c) providing a sacrificial reagent in the solution;
- (d) transferring a charge from the sacrificial reagant to the analyte;
- (e) transferring a charge from the analyte to the electrode, thereby generating an electrical signal;
- (f) repeating steps (d) and (e) to amplify the electrical signal;
- and
- (g) measuring the amplified electrical signal.
A method of detecting relatively low levels of an analyte in solution by amplifying amperometric signals, comprising:
- (a) providing a solution having an analyte therein, the analyte comprising a ferrocene derivative;
- (b) providing an electrode in electrical communication with the solution, the electrode having a coating layer affixed thereon, the coating layer having an upper surface in contact with the solution and a lower surface affixed to the electrode;
- (c) providing a sacrificial reagent in the solution;
- (d) transferring a charge from the sacrificial reagent to the analyte;
- (e) transferring a charge from the analyte to the upper surface of the coating layer;
- (f) transferring a charge from the coating layer to the electrode, thereby generating an electrical signal;
- and
- (g) repeating steps (d)-(f) to amplify the electrical signal.
A bioaffinity ligand binding assay method that employs tagged or labeled analytes of ferrocene to detect DNA, comprising:
- (a) providing a labeled DNA strand having a ferrocene moiety;
- (a) generating a capture DNA strand on a solid bead, the capture DNA strand being combined with the labeled DNA strand;
- (c) exposing the capture DNA strand to a target DNA strand;
- (d) displacing labeled DNA strand from the capture DNA strand;
- (e) attaching the target DNA strand to the capture DNA strand;
- and
- (f) detecting the displaced labeled DNA strand by electrochemical detection methods.
A method of determining the number of ferrocene tagged biomolecules in solution at low detection levels, comprising
- (a) providing at least one ferrocene group;
- (b) linking the ferrocene group with a biomolecule;
- (c) tagging the ferrocene group;
- (d) injecting the tagged ferrocene group, with attached biomolecule, into a flow stream;
- (e) selectively detecting the tagged ferrocene groups;
- and
- (f) determining the amount of biomolecules in solution.
Dependencies are inferred from the claim text.