A selective and sensitive electrochemistry method was developed for the determination of phenacetin on CdSe microspheres modified glassy carbon electrode (GCE). The electrode exhibited an effectively catalytic response to the oxidation of phenacetin, which was testified by the increased oxidation peak current and the decreased oxidation peak potential compared with the bare GCE. The scan rate investigation demonstrated that the electrochemical oxidation was an adsorption-controlled process in the range from 20 to 500 mV s−1. Under optimal determination conditions, the oxidation peak current of phenacetin was proportional to its concentration in the range of 0.5 to 800 μM. The limit of detection was estimated to be 0.1 μM (S/N = 3). The developed method showed good reproducibility, acceptable stability and excellent anti-interference performance. The fabricated electrode was successfully used to determine phenacetin in pharmaceutical formulation samples.
