Hybrid of ZnONPs/MWCNTs for electrochemical detection of aspartame in food and beverage samples

An electrochemical sensor for the detection of aspartame using differential pulse voltammetry (DPV) was developed by modifying a glassy carbon electrode (GCE) with zinc oxide nanoparticles (ZnONPs) dispersed over multiwalled carbon nanotubes (MWCNTs) in dimethylformamide medium. The ZnONPs/MWCNTs/GCE surface area of 12.17 mm2 was able to oxidize aspartame at a potential of 1.70 V in a phosphate buffer of pH 2.0 showing two anodic peaks at 0.398 V and 1.491 V. The characterization of nanocomposite was carried out using transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and cyclic voltammetry (CV). The sensitivity and detection limits obtained with the modified electrode was four-fold greater than that of the unmodified electrode and the concentration of aspartame was found to be 40.36 μM, 27.92 μM and 44.30 μM in Coke zero, Huletts and Sprite zero respectively. The developed method was successfully applied for the determination of aspartame in food samples with a 96% confidence level.

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