A dissolved oxygen sensor based on hot electron induced cathodic electrochemiluminescence at a disposable CdS modified screen-printed carbon electrode

Hot electron induced cathodic electrochemiluminescence (ECL) was found at a disposable CdS modified screen printed carbon electrodes (CdS-SPCEs) during cathodic pulse polarization. The ECL behavior of the modified electrode was investigated with two emissions located at 520 nm and 580 nm. The CdS-SPCEs show very stable and reproducible ECL signal. The ECL intensity was linear with the dissolved oxygen concentration in the range of 1.7–33 mg/L with a detection limit of 0.02 mg/L (S/N = 3). In addition, a possible mechanism for ECL behavior of the modified electrode was proposed. The developed method can be applied to detect the dissolved oxygen concentration or biochemical oxygen demand (BOD).