An ultrasensitive biosensor for glucose based on solid-state electrochemiluminescence on GOx/CdS/GCE electrode

Abstract

In this paper a GOx/CdS/GCE electrode modified with CdS nanorods was prepared using solvothermal route under simple conditions. The electrode shows unexpectedly electrogenerated chemiluminescence (ECL) behavior after immobilization of CdS nanorods on the electrode surface, whereas the CdS nanorod itself only gives weak ECL signal. The possible mechanism of the ECL enhancement on the modified electrode was investigated thoroughly. In addition, the strong ECL emission from the CdS-K₂S₂O₈ electrode was exploited as a useful biosensor for glucose determination. The experimental results demonstrated that this ECL biosensor showed good stability and reproducibility. An excellent linear relationship of the ECL response to he concentration of glucose was obtained within the range of 4.0 × 10⁻¹³ mol L⁻¹ to 4.0 × 10⁻¹⁰ mol L⁻¹ with a detection limit of 2.0 × 10⁻¹³ mol L⁻¹ (S/N = 3).