Electrochemical determination of the antipsychotic medication clozapine by a carbon paste electrode modified with a nanostructure prepared from titania nanoparticles and copper oxide

A nanostructure was prepared from titania nanoparticles and copper oxide (TiO2NP@CuO) and used to modify a carbon paste electrode (CPE). The modified CPE is shown to enable sensitive voltammetric determination of the drug clozapine (CLZ). The sensor was characterized by various techniques and some key parameters were optimized. Under the optimum conditions and at a working potential of 0.6 V (vs. Ag/AgCl), the modified CPE has two linear response ranges, one from 30 pmol L�1 to 4 nmol L�1 of CLZ, the other from 4 nmol L�1 to 10 μmol L�1. The detection limit is as low as 9 pM. The transfer coefficient (α) and catalytic rate constant (kcat) were calculated and the reliability of the sensor was estimated for CLZ sensing in real samples where it gave satisfactory results. Figure not available: see fulltext.. © 2019, Springer-Verlag GmbH Austria, part of Springer Nature

Sonochemical synthesis of ErVO4/MnWO4 heterostructures: Application as a novel nanostructured surface for electrochemical determination of tyrosine in biological samples

Present strategy introduces a novel method established for the synthesis of spherical shape ErVO4/MnWO4 heterostructures by a sonochemical method. This heterostructures with optima morphology can be synthesized by changing power and time ultrasound irradiation without any capping agent. BET analysis revealed that ErVO4/MnWO4 prepared in the presence of ultrasonic procedure has 75 times specific surface area as much as that of those was produced in the absence of ultrasonic rays. A variety of analyses (i.e., BET, XRD, TEM, EDS, FT-IR, and SEM) were applied for characterization of the ErVO4/MnWO4. Next, a selective and sensitive nanostructured sensor based on ErVO4/MnWO4 nanocomposite modified carbon paste electrode (ErVO4/MnWO4/CPE) was constructed for electrochemical detection of tyrosine (Tyr). The electrochemical characterizations were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Compared with the unmodified CPE, the oxidation peak current was significantly enhanced for Tyr. The impact of effective parameters on voltammetric response of Tyr was analyzed with design of experiments (DOE) and response surface methodology (RSM). Under the optimized conditions, the oxidation peak current of Tyr was linear over a range of 0.08�400.0 μM with a detection limit of 7.7 nM. Finally, the usage of the proposed method was confirmed by the recovery tests of Tyr in biological samples. © 201

Introducing a novel nanocomposite consisting of nitrogen-doped carbon nano-onions and gold nanoparticles for the electrochemical sensor to measure acetaminophen

In the present study, gold nanoparticles and nitrogen-doped carbon nano-onions (AuNP/NCNO) in a nanocomposite-based sensor were reported for the electrochemical detection of acetaminophen (APAP). The NCNOs from the fullerene family were prepared using a simple and cost-effective method using aminated nanodiamonds (AM-ND) as a substrate. Nitrogen atoms were introduced into CNO cages during the preparation of these nanostructures by annealing AM-NDs under an inert helium atmosphere and reduced pressure. AuNPs were synthesized using a straightforward method. The nanocomposite profoundly enhanced the active surface area of the glassy carbon electrode and amplified the electron transfer rate. Accordingly, electrocatalysis of the APAP was achieved at the modified electrode surface at 0.38 V vs. Ag/AgCl. Under the optimal conditions, the sensor displayed a linear response for APAP detection ranging from 25 nM to 35 mu M with a limit of detection (LOD) of 9 nM. Potentially interfering drugs, such as ascorbic acid and dopamine, with 5-fold higher concentrations did not interfere with APAP detection. The feasibility of the sensor for APAP detection in tablet and serum samples was successfully evaluated. The qualities of this sensor, including its rapid-response, sensitivity and ease of use, maybe beneficial for potential applications in detecting other drugs

Simultaneous voltammetric sensing of acetaminophen, epinephrine and melatonin using a carbon paste electrode modified with zinc ferrite nanoparticles

A highly selective electrochemical sensor was fabricated based on a modified carbon paste electrode with zinc ferrite nanoparticles (ZnFe2O4 NPs). The nanocomposite has attractive properties such as high surface-to-volume ratio and good electrocatalytic activity towards the drugs acetaminophen (AC), epinephrine (EP), and melatonin (MT), best at working voltages of 0.35, 0.09 and 0.55 V (vs. Ag/AgCl), respectively. The linear ranges (and detection limits) are 6.5-135 (0.4) mu mol L-1 for AC, 5-100 (0.7) mu mol L-1 for EP, and 6.5-145 (3) mu mol L-1 for MT

A carbon paste electrode modified with Al2O3-supported palladium nanoparticles for simultaneous voltammetric determination of melatonin, dopamine, and acetaminophen

The authors have modified a carbon paste electrode with Al2O3-supported palladium nanoparticles (PdNP@Al2O3) to obtain a sensor for simultaneous voltammetric determination of melatonin (MT), dopamine (DA) and acetaminophen (AC). The PdNP@Al2O3 was characterized by scanning electron microscopy and energy-dispersive X-ray spectra. The sensor can detect DA, AC, MT and their mixtures by giving distinct signals at working voltages of typically 236, 480 and 650 mV (vs. Ag/AgCl), respectively. Differential pulse voltammetric peak currents of DA, AC and MT increase linearly in the 50 nmol L-1 - 1.45 mmol L-1, 40 nmol L-1 -1.4 mmol L-1, and 6.0 nmol L-1 - 1.4 mmol L-1 concentration ranges. The limits of detection are 36.5 nmol L-1 for DA, 36.5 nmol L-1 for AC, and 21.6 nmol L-1 for MT. The sensor was successfully used to detect the analytes in (spiked) human serum and drug samples

A nanocomposite prepared from reduced graphene oxide, gold nanoparticles and poly(2-amino-5-mercapto-1,3,4-thiadiazole) for use in an electrochemical sensor for doxorubicin

A nanocomposite was prepared with reduced graphene oxide, gold nanoparticles and an electropolymerized film made from 2-amino-5-mercapto-1,3,4-thiadiazole. An electrochemical sensor for doxorubicin (DOX) was constructed by modifying a glassy carbon electrode (GCE) with the nanocomposite. The modified GCE was studied by electrochemical techniques which showed it to enable highly sensitive sensing of DOX. Response (typically measured at a typical working potential of -0.56 V vs. Ag/AgCl) is linear in the 30 pM to 30 nM and 30 nM to 30 muM DOX concentration ranges, with a limit of detection (LOD) of 9 pM (at an S/N ratio of 3). The method was applied to the determination of DOX in serum and gave recoveries that ranged between 92 and 108. Graphical abstract A combination of materials consisting of reduced graphene oxide (rGO), gold nanoparticles (AuNPs) and an electropolymerized film of 2-amino-5-mercapto-1,3,4-thiadiazole (poly-AMT, PAMT) is described. The nanocomposite was placed on a glassy carbon elkectrode (GCE) in order to fabricate an electrochemical sensor for doxorubicin (DOX)

Introducing a novel nanocomposite consisting of nitrogen-doped carbon nano-onions and gold nanoparticles for the electrochemical sensor to measure acetaminophen

In the present study, gold nanoparticles and nitrogen-doped carbon nano-onions (AuNP/NCNO) in a nanocomposite-based sensor were reported for the electrochemical detection of acetaminophen (APAP). The NCNOs from the fullerene family were prepared using a simple and cost-effective method using aminated nanodiamonds (AM-ND) as a substrate. Nitrogen atoms were introduced into CNO cages during the preparation of these nanostructures by annealing AM-NDs under an inert helium atmosphere and reduced pressure. AuNPs were synthesized using a straightforward method. The nanocomposite profoundly enhanced the active surface area of the glassy carbon electrode and amplified the electron transfer rate. Accordingly, electrocatalysis of the APAP was achieved at the modified electrode surface at 0.38 V vs. Ag/AgCl. Under the optimal conditions, the sensor displayed a linear response for APAP detection ranging from 25 nM to 35 μM with a limit of detection (LOD) of 9 nM. Potentially interfering drugs, such as ascorbic acid and dopamine, with 5-fold higher concentrations did not interfere with APAP detection. The feasibility of the sensor for APAP detection in tablet and serum samples was successfully evaluated. The qualities of this sensor, including its rapid-response, sensitivity and ease of use, maybe beneficial for potential applications in detecting other drugs. © 202

Sensitive sensor based on TiO2NPs nano-composite for the rapid analysis of Zolpidem, a psychoactive drug with cancer-causing potential

In the present study, a sensitive and specific electrochemical sensor is developed based on titanium dioxide and ionic liquid nano-composite (TiO2NPs/IL) for the measurement of Zolpidem (ZLP) as a hypnotic and sleep-promoting drug. The nano-composite provides high surface area and catalytic ability in ZLP oxidation at the modified carbon paste electrode (CPE). The obtained results of the differential pulse voltammetry (DPV) method reflect a wide linear range (0.1�90 μM) and an unprecedented limit of detection (LOD = 33 nM) for the ZLP sensor comparable with previously reported methods. The TiO2NPs/IL/CPE remarkably enriched the electrochemical response to ZLP oxidation and it has good stability, repeatability, and reproducibility. The TiO2NPs/IL/CPE is mechanically stable, cost-effective and simple, with suitable electrochemical and adsorption properties in comparison to the pencil graphite electrode (PGE) and glassy carbon electrode (GCE). The potential applicability of the sensor was successfully applied for distinguishing the ZLP in human plasma and drug formulation samples. © 202

Sensitive sensor based on TiO2NPs nano-composite for the rapid analysis of Zolpidem, a psychoactive drug with cancer-causing potential

In the present study, a sensitive and specific electrochemical sensor is developed based on titanium dioxide and ionic liquid nano-composite (TiO2NPs/IL) for the measurement of Zolpidem (ZLP) as a hypnotic and sleep-promoting drug. The nano-composite provides high surface area and catalytic ability in ZLP oxidation at the modified carbon paste electrode (CPE). The obtained results of the differential pulse voltammetry (DPV) method reflect a wide linear range (0.1−90 μM) and an unprecedented limit of detection (LOD = 33 nM) for the ZLP sensor comparable with previously reported methods. The TiO2NPs/IL/CPE remarkably enriched the electrochemical response to ZLP oxidation and it has good stability, repeatability, and reproducibility. The TiO2NPs/IL/CPE is mechanically stable, cost-effective and simple, with suitable electrochemical and adsorption properties in comparison to the pencil graphite electrode (PGE) and glassy carbon electrode (GCE). The potential applicability of the sensor was successfully applied for distinguishing the ZLP in human plasma and drug formulation samples. © 202