High sensitive determination of theophylline based on gold nanoparticles/l-cysteine/Graphene/Nafion modified electrode

Simultaneous Voltammetric Determination of Theophylline and Guaifenesin Using a Multiwalled Carbon Nanotube‐Ionic Liquid Modified Glassy Carbon Electrode

“…The plot of peak potential versus pH ( Figure 3B,D) showed straight lines between 4.0-10.0 (y = À0.017x + 1.284) and 2.0-8.0 (y = À0.054x + 1.305) for GF and TP, respectively (R 2 > 0.98). This is in consistent with previous reports [26][27][28].…”

“…Our preliminary studies showed that cyclic voltammetry of both compounds were associated with irreversible oxidation processes in aqueous solutions over a wide pH range (2-10), which were in agreement with previously reported data [26,27]. The effect of pH on the electrochemical behaviors of TP and GF was studied individually ( Figure 3A,C), and the results showed that, the oxidation of both compounds are pH dependent and maximum peak currents could be observed in acidic media for both cases.…”

“…The electrochemical behaviors of TP and GF have been individually studied on common solid electrodes [26,27]. Our preliminary studies showed that cyclic voltammetry of both compounds were associated with irreversible oxidation processes in aqueous solutions over a wide pH range (2-10), which were in agreement with previously reported data [26,27].…”

Selective electrochemical sensor for theophylline based on an electrode modified with imprinted sol–gel film immobilized on carbon nanoparticle layer

“…5B). It revealed that the oxidation reaction of TP was totally irreversible, which was in agreement with previous reports [50,51]. At the bare GCE (Fig.…”

“…However, electrochemical methods have a main drawback of TP determination with common electrode materials (e.g., glassy carbon, metals) since its oxidation occurs at high positive potential, thus overlapping with the discharge of the electrolytic solution. To deal with this problem, the electrodes are modified with several materials such as carbon nanotubes, graphene oxide and manganese oxide nanoparticles [12][13][14][15][16].…”