A novel non-enzymatic glucose sensor based on the modification of carbon paste electrode with CuO nanoflower: Designing the experiments by response surface methodology (RSM)

A non enzymatic modified electrode was constructed based on the modification of carbon paste electrode with CuO nanoflower (CuO-CPE). The raw and modified samples were characterized by XRD, TEM, SEM-EDX and X-ray mapping techniques. The proposed CuO-CPE showed a well voltammetric peak pair in cyclic voltammetry which of peak currents were decreased in the presence of glucose. Hence, this decrease in peak current was used for voltammetric determination of glucose. To evaluate interactions between the influencing variables, experiments were designed by response surface methodology (RSM) and the results showed CuO%-pH have the most effect on square wave voltammetric response. The best response was obtained in a run including 20% CuO modifier, pH 3.6, amplitude 0.106V, step potential 0.0074V and frequency 17.75Hz. Calibration curve was constructed and a linear response between ΔIp (difference of peak current in the presence and absence of glucose in SqW voltammograms) and glucose concentration was obtained in concentration range from 0.06 to 10mmolL-1 [calibration equation: ΔI (μA)=91.35 Cglucose+523.12, R2=0.9967] with detection and quantification limits of 7.49×10-10 and 2.49×10-9molL-1, respectively. The modified electrode can be used satisfactory in determination of glucose in real samples such as human blood serum.