SmHCF/multiwalled carbon nanotube modified glassy carbon electrode for the determination of codeine

- The Glassy carbon electrode surface was modified with the electrodeposition of the SmHCF in the presence of MWCNT
- The modified electrode shows excellent electrocatalytic activity toward Codeine
- Electrocatalytic effect arising from the unpaired 'd' or "f" electrons and vacant d or f orbitals of metal hexacyanofferate
- Two different linear ranges: 2 × 10 -7 - 1 × 10- 6 and 1 × 10- 6 - 2 × 10- 5 and detection limit of 6 × 10 -8 were observed

A new organic-inorganic hybrid [SmHCF/(MWCNT)] on the surface of glassy carbon electrode was synthesized by electrochemical process and was used for the sensitive and selective determination of codeine by employing voltammetric techniques. Scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry were used to characterize and specify performance of the modified electrode, and the results were compared with the other conclusions. The SmHCF-MWCNT modified electrode offers an excellent selectivity, stability and reproducibility voltammetric measurements of COD compared with the bare, SmHCF and MWCNT modified glassy carbon electrodes. The enhanced electrocatalytic activity associated with COD is indicated from lowering the potential of the oxidation process (starting around 0.75 vs. Ag/AgCl) and the high sensitivity over the entire potential range. The linear dynamic range relationships between oxidation peak currents and COD concentration in two different linear ranges: 2 × 10− 7-1 × 10− 6 (slope = 9.842 μA μM− 1) and 1 × 10− 6-2 × 10− 5 (slope = 0.778 μA μM− 1) with a detection limit of 6 × 10− 8 for COD were observed. The accuracy of the modified electrode was indicated by COD recovery test in the real samples as human serum samples.