Photoresponsive redox detection and discrimination

Claim 1

A photoresponsive device for making at different sites a plurality of determinations of a redox substance capable of modifying an electrical signal resulting from irradiation of a photoresponsive element, said device comprising: a photoresponsive element having an irradiation receiving surface; irradiation means for irradiating at least two sites on said surface to provide distinguishable signals; a counterelectrode; means for creating a potential at said element with respect to said counterelectrode; first and second container means for retaining electrically responsive media in communication with a first and second one of said two sites, respectively; means adapted for providing impedance between each of said sites and said counterelectrode; and means for measuring the electrical photoresponse during irradiation of a site.

Claim 20

A method for substantially simultaneously determining a redox substance in a plurality of volumes of an electrically responsive medium, employing a photoresponsive element having a common lead through an electrical circuit to a counterelectrode, wherein said substance is capable of modulating the photoresponse of said element; said method comprising: maintaining a separate electrical communication having impedance between each of a plurality of sites on a photoresponsive surface of said element and said counterelectrode through said electrically responsive medium; irradiating said surface at said sites at different times in a predetermined sequence for defined periods of time at each of said sites, each site being associated with a different one of said volumes; and determining by means of said circuit the presence of said substance in each of said volumes by the effect of said substance on the photoresponse resulting from said irradiation.

Claim 21

A method for substantially simultaneously determining a redox substance in a plurality of volumes of an electrically responsive medium, employing a photoresponsive element having a common lead through an electrical circuit to a counterelectrode, wherein said substance is capable of modulating the photoresponse of said element; said method comprising: maintaining a separate electrical communication having impedance between each of a plurality of sites on a photoresponsive surface of said element and said counterelectrode through said electrically responsive medium; irradiating said surface at said sites at different times in a predetermined sequence for defined periods of time at each of said sites, each site being associated with a different one of said volumes; and determining by means of said circuit the presence of said substance in each of said volumes by the effect of said substance on the photoresponse resulting from said irradiation.

Claim 36

A method for determining the presence of an analyte in a sample, which analyte is a member of a first specific binding pair consisting of ligand and receptor, said method employing: (a) a photoresponsive electrode having an irradiation surface; (b) a counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; (d) means for providing separate resistive couplings between said counterelectrode and a plurality of sites on said surface; (e) a binding surface for binding a member of a specific binding pair, which surface is said irradiation surface or a facing surface in close spaced apart juxtaposition to said irradiation surface; and (f) specific binding means for specifically binding one of said members of said first specific binding pair to said binding surface; said method comprising: in an aqueous assay medium, combining components with said specific binding means, said assay components including a sample, a labeled specific binding pair member, which labeled specific binding pair member is a member of said first pair or capable of binding to, either directly or indirectly, a member of said first pair, wherein said label is a member of a system capable of modulating the electrical photoresponse of said photoresponsive electrode by means of a change in redox potential, and any additional members of said system; irradiating said plurality of sites on said irradiation surface in relation to individual volumes of said combined components at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as modulated by said system by means of said circuit as indicative of the presence of said analyte in said sample.

Claim 37

A method for determining the presence of an analyte in a sample, which analyte is a member of a first specific binding pair consisting of ligand and receptor, said method employing: (a) a photoresponsive electrode having an irradiation surface; (b) a counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; (d) means for providing separate resistive couplings between said counterelectrode and a plurality of sites on said surface; (e) a binding surface for binding a member of a specific binding pair, which surface is said irradiation surface or a facing surface in close spaced apart juxtaposition to said irradiation surface; and (f) specific binding means for specifically binding one of said members of said first specific binding pair to said binding surface; said method comprising: in an aqueous assay medium, combining components with said specific binding means, said assay components including a sample, a labeled specific binding pair member, which labeled specific binding pair member is a member of said first pair or capable of binding to, either directly or indirectly, a member of said first pair, wherein said label is a member of a system capable of modulating the electrical photoresponse of said photoresponsive electrode by means of a change in redox potential, and any additional members of said system; irradiating said plurality of sites on said irradiation surface in relation to individual volumes of said combined components at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as modulated by said system by means of said circuit as indicative of the presence of said analyte in said sample.

Claim 43

A method for determining the presence of an enzyme substrate in a medium, wherein the product of said substrate results in the production of product, capable of producing either directly or indirectly a detectable redox potential, said method employing: (a) a photoresponsive semiconductor electrode having an irradiation surface; (b) at least one counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; (d) a binding surface for binding said enzyme at a plurality of sites; said method comprising: providing separate resistive couplings between said counterelectrode and each of said sites; contacting said enzyme at each of said sites with an aqueous medium containing said substrate and any additional components necessary for the enzymatic catalyzed reaction; irradiating said sites on said irradiation surface at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as modified by said system by means of said circuit as a measure of the amount of said substrate present.

Claim 44

A method for determining the presence of an enzyme substrate in a medium, wherein the product of said substrate results in the production of product, capable of producing either directly or indirectly a detectable redox potential, said method employing: (a) a photoresponsive semiconductor electrode having an irradiation surface; (b) at least one counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; (d) a binding surface for binding said enzyme at a plurality of sites; said method comprising: providing separate resistive couplings between said counterelectrode and each of said sites; contacting said enzyme at each of said sites with an aqueous medium containing said substrate and any additional components necessary for the enzymatic catalyzed reaction; irradiating said sites on said irradiation surface at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as modified by said system by means of said circuit as a measure of the amount of said substrate present.

Claim 47

A method for determining the presence of one or more microorganisms in a medium, said method employing: (a) a photoresponsive electrode having an irradiation surface having a plurality of sites; (b) at least one counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; said method comprising: providing separate resistive couplings between said counterelectrode and each of said sites; contacting said medium at each of said sites under conditions where said microorganism remains viable and produces at least one metabolic product capable of modulating the photoresponsive of said photoresponsive electrode by means of a change in the detectable redox potential of said medium; irradiating said sites on said irradiation surface at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as modified by said metabolic product by means of said circuit as an indication of the presence of a microorganism.

Claim 48

A method for determining the presence of one or more microorganisms in a medium, said method employing: (a) a photoresponsive electrode having an irradiation surface having a plurality of sites; (b) at least one counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; said method comprising: providing separate resistive couplings between said counterelectrode and each of said sites; contacting said medium at each of said sites under conditions where said microorganism remains viable and produces at least one metabolic product capable of modulating the photoresponsive of said photoresponsive electrode by means of a change in the detectable redox potential of said medium; irradiating said sites on said irradiation surface at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as modified by said metabolic product by means of said circuit as an indication of the presence of a microorganism.

Claim 50

A method for detecting the presence of an analyte in a medium, said method employing: (a) a photoresponsive electrode having an irradiation surface having a plurality of sites; (b) at least one counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; said method comprising: providing separate resistive couplings between said counterelectrode and each of said sites; contacting said medium at each of said sites, wherein said medium contains horseradish peroxidase, hydrogen peroxide and methylene blue, and the amount of horseradish peroxidase in said medium is related to the amount of analyte in said medium, said horseradish peroxidase catalyzing the oxidation of methylene blue; irradiating said sites on said irradiation surface at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as a result of the reaction of the methylene blue at each of said sites.

Claim 51

A method for detecting the presence of an analyte in a medium, said method employing: (a) a photoresponsive electrode having an irradiation surface having a plurality of sites; (b) at least one counterelectrode; (c) an electrical circuit connecting said photoresponsive electrode and counterelectrode and maintaining said electrodes in a predetermined potential relationship; said method comprising: providing separate resistive couplings between said counterelectrode and each of said sites; contacting said medium at each of said sites, wherein said medium contains horseradish peroxidase, hydrogen peroxide and methylene blue, and the amount of horseradish peroxidase in said medium is related to the amount of analyte in said medium, said horseradish peroxidase catalyzing the oxidation of methylene blue; irradiating said sites on said irradiation surface at different times in accordance with a predetermined schedule; and determining the electrical photoresponse as a result of the reaction of the methylene blue at each of said sites.