Multiwall carbon nanotube modified glassy carbon electrode as voltammetric sensor for the simultaneous determination of ascorbic acid and caffeine

► Performance of bare and modified GCE for the study of oxidation of drugs. ► MWCNT/MGCE used for determination of AA and CAF in various samples. ► It is demonstrated that the modified electrode is better than the bare GCE. ► AA and CAF are quantified in tea leaves, coffee, cold drink, urine samples.