A method for detecting the presence and/or concentration of a target analyte in a sample, comprising the steps of: (a) combining, either simultaneously or wholly or partially sequentially: a sample suspected of containing the target analyte; an electrode having target analyte or an analog thereof attached thereto, wherein analog refers to a substance which comprises the same basic carbon skeleton and carbon functionality in its structure as a target analyte but comprising one or more substitutions thereto, or a compound that binds to the same binding partner as the target analyte but that is chemically different from the target analyte, the electrode being capable of generating singlet oxygen in its excited state; and a composition comprising a singlet oxygen-activatable chemiluminescent compound capable of directly or indirectly binding to the target analyte or analog thereof attached to the electrode or to target analyte present in the sample; (b) allowing the binding of to the target analyte or analog thereof bound to the electrode and to target analyte present in the sample, whereby binding of to the target analyte or analog thereof bound to the electrode brings the electrode into close proximity to the chemiluminescent compound, and whereby binding of to target analyte present in the sample prevents association of with the electrode; (c) washing the electrode with a composition comprising a singlet oxygen generator; (d) applying a potential to the electrode to generate singlet oxygen, wherein generation of singlet oxygen in close proximity to the chemiluminescent compound causes the activation of the chemiluminescent compound bound to the target analyte attached to the electrode; (e) determining the amount of chemiluminescence generated by the activated chemiluminescent compound; (f) optionally repeating steps (b) - (e); and (g) detecting the presence and/or concentration of the target analyte by analyzing the amount of chemiluminescence so produced, wherein the amount of chemiluminescence is inversely proportional to the amount of target analyte in the sample. (a) combining, either simultaneously or wholly or partially sequentially: a sample suspected of containing the target analyte; an electrode having target analyte or an analog thereof attached thereto, wherein analog refers to a substance which comprises the same basic carbon skeleton and carbon functionality in its structure as a target analyte but comprising one or more substitutions thereto, or a compound that binds to the same binding partner as the target analyte but that is chemically different from the target analyte, the electrode being capable of generating singlet oxygen in its excited state; and a composition comprising a singlet oxygen-activatable chemiluminescent compound capable of directly or indirectly binding to the target analyte or analog thereof attached to the electrode or to target analyte present in the sample; a sample suspected of containing the target analyte; an electrode having target analyte or an analog thereof attached thereto, wherein analog refers to a substance which comprises the same basic carbon skeleton and carbon functionality in its structure as a target analyte but comprising one or more substitutions thereto, or a compound that binds to the same binding partner as the target analyte but that is chemically different from the target analyte, the electrode being capable of generating singlet oxygen in its excited state; and a composition comprising a singlet oxygen-activatable chemiluminescent compound capable of directly or indirectly binding to the target analyte or analog thereof attached to the electrode or to target analyte present in the sample; (b) allowing the binding of to the target analyte or analog thereof bound to the electrode and to target analyte present in the sample, whereby binding of to the target analyte or analog thereof bound to the electrode brings the electrode into close proximity to the chemiluminescent compound, and whereby binding of to target analyte present in the sample prevents association of with the electrode; (c) washing the electrode with a composition comprising a singlet oxygen generator; (d) applying a potential to the electrode to generate singlet oxygen, wherein generation of singlet oxygen in close proximity to the chemiluminescent compound causes the activation of the chemiluminescent compound bound to the target analyte attached to the electrode; (e) determining the amount of chemiluminescence generated by the activated chemiluminescent compound; (f) optionally repeating steps (b) - (e); and (g) detecting the presence and/or concentration of the target analyte by analyzing the amount of chemiluminescence so produced, wherein the amount of chemiluminescence is inversely proportional to the amount of target analyte in the sample.