Development of Simple Electrochemical Sensor for Selective Determination of Methadone in Biological Samples Using Multi‐walled Carbon Nanotubes Modified Pencil Graphite Electrode

Abstract

The electrochemical sensor was developed for determination of methadone (MTD) using multi‐walled carbon nanotubes (MWCNT) modified pencil graphite electrode (MWCNT‐PGE). It was found that the oxidation peak current of MTD at the MWCNT‐PGE was greatly improved compared with that of the bare‐PGE. At the MWCNT‐PGE, well‐defined anodic peak of MTD was observed at about 0.7 V (in pH 7 solution). The influence of several parameters on the determination of MTD was investigated. At optimum experimental conditions, differential pulse voltammetry (DPV) was used for determination of MTD, which exhibited a linear calibration graph of Ip versus MTD concentration in the range of 0.1–15 µM with a correlation coefficient of 0.9992. The calculated detection limit for S/N = 3 was 87 nM. It has been shown that the peaks obtained for oxidation of ascorbic acid (AA), uric acid (UA) and MTD in their mixture could be well resolved by differential pulse voltammetry, permitting us to develop a sensitive and selective electrochemical sensor for determination of MTD in the presence of AA and UA. Finally, MWCNT‐PGE was used for determination of MTD in biological samples, such as human serum and urine, using the standard addition procedure and the results were quite promising.

Pretreated Pencil Graphite Electrode as a Versatile Platform for Easy Measurement of Diclofenac Sodium in a Number of Biological and Pharmaceutical Samples

“…Also, the performance of this PPGE is comparable to that of pencil graphite electrodes modified by other materials . Besides, because of nonuse of expensive materials for electrode modification and easy‐to‐use application of this sensor, this sensor is superior to other modified pencil graphite electrodes.…”

“…Recently, we utilized an electrochemically pretreated pencil graphite electrode (PPGE) successfully to develop various DNA hybridization biosensors . Additionally, PPGE was successfully used for the selective determination of dopamine, uric acid (UA), morphine, methadone and methamphetamine in biological and seized samples. Electrochemical pretreatment of the pencil graphite electrode (PGE) appears to be a simple and better strategy and is less time consuming in comparison with other modification procedures of the electrode surface .…”

Pencil Graphite Electrodes: A Versatile Tool in Electroanalysis

“…Carbon nanomaterials, as carbon nanotubes (CNTs) [ 120 , 135 , 158 , 204 , 205 ], nanofibers [ 206 ], nanopowders [ 68 ], or graphene [ 28 , 147 , 175 , 177 ], are largely used for the development of electrochemical sensors. CNTs are NS very suitable for PGEs surface modification due to their nanometer dimensions, high stability, large specific area, good conductivity, electronic properties, and topological defects conferring them excellent catalytic characteristics which enable the promotion of redox reactions at the electrode surface (improvement of electron transfer rate and redox reversibility), and the ability to reduce the electrode surface fouling and the electrolyte impedance [ 3 , 120 , 158 , 161 , 205 ].…”

“…In order to demonstrate the modification of a surface, different techniques are used to investigate and to compare the morphology and/or the electrochemical characteristics of the respective surface and/or of the modifier, before, during, or after the modification process. For surface morphology of bare or modified PGE investigations, different techniques of electron [ 3 , 15 , 24 , 28 , 29 , 32 , 34 , 35 , 54 , 60 , 65 – 67 , 85 , 111 , 118 – 122 , 126 – 128 , 130 , 135 , 141 – 143 , 145 – 148 , 158 , 161 , 170 , 173 , 175 , 178 , 181 – 183 , 189 , 198 , 200 , 204 , 205 , 210 , 216 , 218 , 219 ] and atomic force microscopy [ 28 , 29 , 60 , 65 – 67 , 112 , 126 , 172 , 198 , 205 ] are widely used. Sometimes, scanning electron microscopy (SEM) was coupled with energy-dispersive X-ray spectroscopy analysis [ 130 , 143 , 149 , 152 , 156 , 172 , 187 , 188 , 203 – 205 ].…”

“…Electrochemical impedance spectroscopy (EIS) provided information on impedance changes at the electrode surface and therefore on the appearance of surface modifications enabling thus the differentiation between unmodified and modified electrodes [ 3 , 54 , 60 , 61 , 104 , 119 , 127 , 140 , 149 , 161 , 170 , 173 , 182 , 198 , 205 , 210 , 216 ], while CV is useful to characterize an electrode from electrochemical point of view or to investigate the electroactivity of conducting polymers, providing information about the formation, the potential, and the anodic/cathodic peak potentials of the polymer [ 3 , 15 , 24 , 28 , 32 , 43 , 54 , 60 – 63 , 66 , 67 , 72 , 104 , 111 , 114 , 117 , 118 , 120 – 122 , 125 , 127 , 135 , 140 , 144 , 145 , 149 , 152 , 158 , 161 , 168 , 170 , 175 , 177 , 181 , 183 , 192 , 193 , 203 – 205 , 208 , 210 ].…”