A method of detecting an analyte in a sample, comprising: (a) allowing the sample to react with at least one reactant contained in a fluidic device, said device comprising: (i) an assay assembly for yielding an optical signal that is indicative of the presence of the analyte, said assay assembly comprising: reagent chambers comprising at least one reagent used in said assay, wherein the reagents used in the assay comprise an enzyme conjugate and an enzyme substrate; and at least one reaction site comprising a reactant that binds said analyte; and (ii) a quencher assembly in fluidic communication with said assay assembly, wherein said quencher assembly comprises a waste chamber and a quenching site comprising an absorbent material incorporating a quenching agent wherein the quenching agent is an organic compound with an absorbance spectrum overlapping the fluorescence emission spectrum of a fluorescent species used to enhance a chemiluminescent signal or a singlet oxygen quencher; (b) collecting reagents in the waste chamber which have not bound to the reaction site, and quenching optical signals from such unbound reagents with said quenching agent; and (c) detecting said optical signal thereby detecting the analyte in the sample. (a) allowing the sample to react with at least one reactant contained in a fluidic device, said device comprising: (i) an assay assembly for yielding an optical signal that is indicative of the presence of the analyte, said assay assembly comprising: reagent chambers comprising at least one reagent used in said assay, wherein the reagents used in the assay comprise an enzyme conjugate and an enzyme substrate; and at least one reaction site comprising a reactant that binds said analyte; and (ii) a quencher assembly in fluidic communication with said assay assembly, wherein said quencher assembly comprises a waste chamber and a quenching site comprising an absorbent material incorporating a quenching agent wherein the quenching agent is an organic compound with an absorbance spectrum overlapping the fluorescence emission spectrum of a fluorescent species used to enhance a chemiluminescent signal or a singlet oxygen quencher; (i) an assay assembly for yielding an optical signal that is indicative of the presence of the analyte, said assay assembly comprising: reagent chambers comprising at least one reagent used in said assay, wherein the reagents used in the assay comprise an enzyme conjugate and an enzyme substrate; and at least one reaction site comprising a reactant that binds said analyte; and reagent chambers comprising at least one reagent used in said assay, wherein the reagents used in the assay comprise an enzyme conjugate and an enzyme substrate; and at least one reaction site comprising a reactant that binds said analyte; and (ii) a quencher assembly in fluidic communication with said assay assembly, wherein said quencher assembly comprises a waste chamber and a quenching site comprising an absorbent material incorporating a quenching agent wherein the quenching agent is an organic compound with an absorbance spectrum overlapping the fluorescence emission spectrum of a fluorescent species used to enhance a chemiluminescent signal or a singlet oxygen quencher; (b) collecting reagents in the waste chamber which have not bound to the reaction site, and quenching optical signals from such unbound reagents with said quenching agent; and (c) detecting said optical signal thereby detecting the analyte in the sample.