A New Sensitive Sensor for Simultaneous Differential Pulse Voltammetric Determination of Codeine and Acetaminophen Using a Hydroquinone Derivative and Multiwall Carbon Nanotubes Carbon Paste Electrode

Figure 2

Cyclic voltammograms of HTP-MWCNT-CPE in a 0.15 M phosphate buffer solution (pH 7.0) containing 0.11 mM of codeine at different scan rates. The numbers of 1–10 correspond to scan rates of 2.5, 5, 7.5, 10, 12.5, 15, 17,5, 20, 22.5, and 25 mV s⁻¹. Insets: (a) variation of the electrocatalytic peak currents versus the square root of scan rate and (b) variation of the scan rate normalized peak current () versus the scan rate.