Construction of a sensitive electrochemical sensor for diphenhydramine and 8-chlorotophylline as a dimenhydrinate drug based on copper nanoparticles and polyalizarin yellow at two applied potentials

Dimenhydrinate (DMH) is a salt composed by the combination of two active pharmaceutical ingredients: diphenhydramine (DIP) and 8-chlorotheophylline (CTP). In this work, the glassy carbon electrode was electrochemically deposited in two steps. The electrode was first inserted in the Alizarin Yellow R (AYR) solution and it was placed on the surface of the electrode after 8 scans. In order to modify the electrode with copper nanoparticles, the prepared electrode was first inserted into the copper sulfate solution and coated with copper nanoparticles using cyclic voltammetry CuNps/PAYR/GCE was fabricated. SEM images showed that the copper nanoparticles were deposited on the electrode. The electrocatalytical effects of the electrochemical sensor were also studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. This electrode was used for detection simultaneously of DIP (OX1) and CTP (OX2) in pharmaceutical samples. The results showed that the highest sensitivity for DMH was obtained at pH = 10. Finally, Also, the detection of limit, sensitivity and linear range were calculated as 0. 29 µM, 0.043 and 1–3000 µM respectively. CuNps/PAYR/GCE presented considerable advantages for instance high sensitivity, used for real samples, simple preparation, low detection of limit, and specially the simultaneous oxidation of CTP and DIP for detection of DMH. Graphical abstract