Fabrication of electrochemical sensor based on molecularly imprinted polymer and nanoparticles for determination trace amounts of morphine

Abstract

A simple and rapid electrochemical method developed for the detection of trace amounts of morphine (MO) at the surface of modified pencil graphite electrode (PGE) with multiwall carbon nanotubes (MWCNTs), molecularly imprinted polymer (MIP), and gold nanoparticles (AuNPs).Various types of electrochemical methods containing cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) were employed to probe the characteristics of the constructed electrode toward morphine. After optimization of several effective parameters, the calibration curve by SWV was linear in two linear domains, over the range of 0.008 to 5 μmol L −1 vs. Ag/AgCl, and the detection limit was 2.9 nM. The relative standard deviation (RSD) for six replicate determinations of 0.05 μmol L −1 MO was found to be 2.57 % (S/N = 3). Finally, the ability of the electrochemical sensor was successfully applied for MO determination in real samples such as human urine and plasma.

Pencil Graphite Electrodes: A Versatile Tool in Electroanalysis

“…Nanoparticles (NP) immobilized on electrodes surfaces improve the electrodes electrochemical characteristics by mediating the electron transfer reactions of electroactive species. NP-modified electrodes can be obtained by electrodeposition [ 140 , 161 , 203 ] or by simply immersion of the pencil lead into the NP solution [ 25 , 32 , 188 ]. Tl 2 O 3 -NS obtained by a sonochemical method were used to develop a Tl 2 O 3 -NS/MWCNTs modified PGE for Cu 2+ trace sensing with a LD of 4.63 nM Cu 2+ .…”

“…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 ].…”

“…To enhance the polymers ability to recognize and bind selective the analyte, they can be molecularly imprinted with the target/analyte molecule (template) by chemical grafting, soft lithography, molecular self-assembly, electropolymerization (galvanostatic, potentiostatic, and cyclic voltammetric methods), irradiation, or heating [ 118 , 168 , 169 , 173 ], followed by the template extraction from this polymer resulting a tailor made receptor that can recognize and rebind the analyte according to its shape and functionality. Besides their increased selectivity, molecularly imprinted polymers- (MIP-) modified PGEs have also other advantages like ease of preparation and low-cost and high chemical stability under various circumstances [ 111 , 125 – 127 , 148 , 161 , 175 ], but they also have some possible drawbacks as incomplete template removal, embedding of binding sites, analyte constraint accessibility to the template cavities, and electroinsulating [ 111 , 141 , 175 ]. Hybrid nanocomposites combining the advantages of their constituents (e.g., MIP and nanomaterials) have been used for electrode surface modification in order to overcome the above-mentioned disadvantages of MIPs and to improve the electrochemical and sensing characteristics of the PGE through a synergistic effect.…”

“…Materials of the MWCNTs-MIP-template adduct type were usually obtained by molecular imprinting on nanostructures and can be easily covered onto PGEs [ 61 , 65 , 67 , 111 , 116 , 117 , 136 , 148 , 150 , 159 – 161 ]. Applications and performance characteristics of the above-mentioned and also other modified PGEs are listed in Table 3 .…”

Simultaneous colorimetric determination of morphine and ibuprofen based on the aggregation of gold nanoparticles using partial least square

“…Table 1 shows a comparison between the results obtained by the present method and those obtained by other methods reported for the determination of these drugs. As can be seen in Table 1 , present method had a good detection limit and linear range compared to those obtained from reverse phase-high performance liquid chromatography (RP-HPLC), electrochemical method, liquid chromatography- mass spectrometry (LC-MS-MS), gas chromatography- mass spectrometry (GC-MS) and direct aqueous derivatization methods [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] . It should be highlighted that the major advantages of this method were use of very simple method for simultaneous determination of these drugs.…”