Electrochemical determination of theophylline in foodstuff, tea and soft drinks based on urchin-like CdSe microparticles modified glassy carbon electrode

► Urchins-like CdSe microparticles modified glassy carbon electrode was prepared. ► A simple and sensitive electrochemical method was developed for theophylline determination. ► Theophylline was determined in tea and soft drink samples. ► The developed method showed excellent selectivity, sensitivity and reproducibility.