Highly sensitive voltammetric sensor based on immobilization of bisphosphoramidate-derivative and quantum dots onto multi-walled carbon nanotubes modified gold electrode for the electrocatalytic determination of olanzapine

Voltammetric Electronic Tongue for the Simultaneous Determination of Three Benzodiazepines

“…The study of BZs by electrochemical techniques is centered on the determination and the quantification of a single BZ at a time. As an example of individual BZ studies we mention determining clonazepam in beverages and serum samples using screen printed electrodes [13] or using polyaniline/graphene oxide nanocomposites [14]; detecting diazepam by dendritic silver nanostructures supported by graphene [15], studying its redox behavior in drinks by adsorptive stripping voltammetry [16], or by the use of fullerene-functionalized carbon nanotubes [17]; determining lorazepam by polypyrrole@sol-gel@gold nanoparticles pencil graphite electrode [18]; quantifying olanzapine using quantum dots onto modified multiwalled carbon nanotubes gold electrode [19]; and, lastly, sensing flunitrazepam in screen-printed electrodes [20], or in alcoholic and soft drinks by screen-printed drop-volume cells [21]. The determination of several BZs can be found in the recent literature as the determination of diazepam and oxazepam in biological fluids using modified carbon paste electrodes [22], or with the use of a multiwall carbon nanotube-ionic liquid paste electrode [23]; using a boron-doped diamond electrode to determine bromazepam and alprazolam [24]; an attempt to determine olanzapine and risperidone modifying gold electrodes with carbon nanotubes [25]; and using a modified bentonite sonogel carbon electrode to determine diazepam chlordiazepoxide determined in urine [26].…”

An advanced and Facile Synthesized Graphene/Magnetic Fe3O4 Nanoparticles Platform for Subnanomolar Voltammetric Determination of Antipsychotic Olanzapine Drug in Human Plasma

“…1 A wide range of analytical methods has been reported for the analysis of Olanzapine in its pure, dosage forms and in biological fluids. These methods comprised spectrophotometry, [2][3][4][5][6][7][8][9][10][11] chromatography [12][13][14][15][16][17][18][19][20][21][22][23] and voltammetry [24][25][26][27][28][29][30][31] {at glassy carbon electrode (GCE), 24,25 and at various voltammetric sensors based on bisphosphoramidate-derivative and quantum dots onto multi-walled carbon nanotubes/Au electrode, 26 Fe 3 O 4 -Ag core-shell magnetic nanoparticles/CPE, 27 carbon nanotubes/Au electrode, 28 a bilayer of MWCNT/benzene disulfonate-doped polypyrrole/GCE, 29 gold nanoparticles and glutamine in a micellar medium/CPE 30 and with amine-functionalized TiO 2 /MWCNT nanocomposite/GCE, 31 }, (Table I). Though most of the reported chromatographic methods 12,[15][16][17][...…”

“…32 With the mean daily oral dose of Olanzapine drug (5-40 mg Olanzapine tablets), 15,[33][34][35] the lowest plasma concentration was in the range of 0.10-1.20 ng ml −1 (3.20 × 10 −10 -3.84 × 10 −9 M). However, the reported voltammetric methods [24][25][26][27][28][29][30][31] have no any available LOQ or LOD values in human plasma (Table I). Besides, the reported Olanzapine determinations in bulk form at bare 24,25 and the modified electrodes [26][27][28][29][30][31] have inadequate LOQ values (1.19 × 10 -8 to 6.40 × 10 -4 M) for clinical pharmacokinetic study.…”

“…However, the reported voltammetric methods [24][25][26][27][28][29][30][31] have no any available LOQ or LOD values in human plasma (Table I). Besides, the reported Olanzapine determinations in bulk form at bare 24,25 and the modified electrodes [26][27][28][29][30][31] have inadequate LOQ values (1.19 × 10 -8 to 6.40 × 10 -4 M) for clinical pharmacokinetic study. This encouraged us to develop a more sensitive voltammetric sensor for quantification of Olanzapine in human plasma.…”

“…Most of the reported sensors for determination of Olanzapine were based on multiwall carbon nanotubes (MWCNT). 26,28,29,31 However, graphene (GR) is rather preferred to CNT as an electrode modifier not only due to its simple and cost-effective preparation but also due to its sp 2 hybridization, unique basal plane structure (which make it possible for GR to load microspheres with diameter size even bigger than several hundred nanometers), better conductivity and extremely high surface area which influence its electrochemical performance. [36][37][38] The 2D hexagonal lattice graphene also emerged as an ideal candidate which has captured enormous interests and grown explosively in electrochemical sensors.…”