Electroanalysis of Diazepam on Nanosize Conducting Poly (3-Methylthiophene) Modified Glassy Carbon Electrode

Abstract

A glassy carbon electrode (GCE) was modified with nanosize poly (3-methylthiophene) (P3MT) and used for the sensitive voltammetric determination of diazepam. The cyclic voltammetric response of the bare GCE was compared with the P3MT modified electrode. Electrochemical impedance response of diazepam on modified GCE was studied by various concentrations of diazepam from 0.2 μM to 0.6 μM. The poly (3-methylthiophene) modified glassy carbon electrode (P3MT/GCE) can greatly enhance the peak currents and the detection sensitivity of diazepam under optimal conditions. The quantitative analysis of diazepam was made by the DPSV method. The experimental results showed that the peak current increased with the increase in concentration of diazepam. A calibration was made, which indicated the linear dependence of peak current with concentration (ip = 13.31Conc. + 0.4359R2 = 0.9948) in the range od determination and ot was found to be good between 0.2 and 1.07 μg/L. The limit of detection was 0.1μg/mL. The reproducibility of the stripping signal was realized in terms of relative standard deviation for 6 identical measurements and was found to be 2.6%. The effect of interference of different cations and anions on the oxidation of diazepam was studied. Real sample analysis of diazepam was also studied through DPSV.

Mercury-free and modification-free electroanalytical approach towards bromazepam and alprazolam sensing: A facile and efficient assay for their quantification in pharmaceuticals using boron-doped diamond electrodes

“…2 demonstrates the CV records for the respective 1×10 −4 mol/L BZ and ALZ solutions using the optimal supporting electrolytes in the potential range from +1.0 to -1.5 V. In both cases, one reduction peak at -1.10 V and -0.84 V at forward scan with the absence of any oxidation peak at reverse scan was observed for BZ and ALZ, respectively, obviously confirming the totally irreversible electrode reactions on BDDEs. This behavior is mostly consistent with those reported for mercury [17,[32][33][34] and chemically modified carbon-based electrodes [18][19][20][21] in BDZs sensing. Besides, it is also apparent from Fig.…”

“…Concerning the analytical performance of BDZ sensing, it should be pointed out that the LODs accomplished by applying BDDEs in the proposed paper are slightly lower with those obtained with m-AgSAE [17] and 3-methylthiophene modified GCE electrodes [19] in acid medium. The usage of other chemically modified electrodes such as MWCNT modified CPE [20] and bentonite modified CPE [21] has resulted in LODs of 10 −8 mol/L using SWV for both cases.…”

“…The literature survey states that hanging mercury drop electrodes (HMDE) [14][15][16] and silver solid amalgam electrode (AgSAE) [17] have been applied to sensitive determination of several BDZs derivatives based on their electrochemical reduction. Besides, various chemically modified carbon-based electrodes such as glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWCNT) [18] and 3methylthiophene [19] as well as carbon paste electrode (CPE) modified with MWCNT [20] and bentonite [21] have been exploited as mercury-free electrochemical platforms for quantifying BDZs. In order to achieve low detection limit (LOD), a modification of carbonbased electrode substrates appeared to be favorable for supporting electron transfer in redox reaction, for decreasing peak potential and principally for increasing sensitivity.…”

Electroanalysis of Ibuprofen on Conducting Polyaniline Nanofiber Coated Glassy Carbon Surface

“…One of the methods used for the modification of electrode surfaces is electropolymerization. Electropolymerization can accelerate transmission of electrons onto the surface of the electrode; it has high selectivity and sensitivity due to the film homogeneity in electrochemical deposition, and it has strong adherence to the electron surface and large surface area [20,21]. Researchers have employed polymeric film modified electrodes to detect organic and inorganic molecules in recent years.…”