A noble electrochemical sensor based on TiO2@CuO-N-rGO and poly (L-cysteine) nanocomposite applicable for trace analysis of flunitrazepam

Flunitrazepam or date rape medication with trade name of Rohypnol belongs to the benzodiazepines branch that is used as a sedative, anesthetic, anticonvulsant, muscle relaxant, and antianxiety drug. It is known as �drug of aggression� because of its very strong and long-lasting effects on the central nervous system. The sedative influence of flunitrazepam drug increases with alcohol drinking, which causes mental and motor disorders and causes the victim to become silent. Due to its criminals use, its accurate measurement is crucial. In this work, a novel electrochemical sensor based on TiO2@CuO-N doped rGO, TiO2@CuO-N-rGO, nano-composite and poly (L-cysteine), poly (L-Cys), is presented for trace analysis of flunitrazepam in aqueous solution. At first, TiO2@CuO-N-rGO nano-composite was synthesized by the sol-gel method and characterized by Raman spectroscopy, Fourier transform infrared, field emission scanning electron microscope, and X-ray diffraction analysis. Then, the suspension of the TiO2@CuO-N-rGO nano-composite was drop casted on the surface of the glassy carbon electrode (GCE/TiO2@CuO-N-rGO). After that, electro-polymerization of l-cysteine on the GCE/TiO2@CuO-N-rGO surface was performed by cyclic voltammetry (CV) method. The electrochemical characteristics of the GCE/TiO2@CuO-N-rGO/poly (L-Cys) surface were evaluated in the solution of ferri/ferrocyanide by electrochemical impedance spectroscopy (EIS) and CV techniques. The increase in current, change in oxidation peak potential, and the appearance of two reduction peaks indicated higher electron transfer rate with well-performed electrochemical process of flunitrazepam at the modified electrode surface compared to the bare GCE. These improvements originate from the synergistic effect of TiO2@CuO-N-rGO nano-composite and poly (L-Cys). Finally, a linear relationship was resulted between the oxidation peak current and the concentration of flunitrazepam in the wide concentration range of 1 nM to 50 μM with a detection limit of 0.3 nM. © 2020 Elsevier B.V

Heat response of prismatic Li-ion cells

The experimental studies of the charge-discharge behavior and heat generation rate of lithium ion cells at different C-rates are conducted in this paper. We are extending this process to monitor and control the thermal behavior of Liion batteries by using phase change material (PCM) as a passive thermal management method to absorb and conduct heat to and from lithium-ion battery modules

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

Fabrication of a new electrochemical sensor based on screen-printed carbon electrode/amine-functionalized graphene oxide-Cu nanoparticles for Rohypnol direct determination in drink sample

Rohypnol or Flunitrazepam belongs to benzodiazepines (Schedule IV) with much higher and long-lasting effects on the central nervous system. Unfortunately, it is used in suicide and aggression. Since it can eventually be detected in the urine within 72 h, it is essential to measure it quickly and accurately. In this work, a new electrochemical sensor for the Rohypnol measurement was fabricated based on a modified screen-printed carbon electrode (SPCE). The SPCE surface was modified with amine-functionalized graphene oxide sheets reinforced through Cu nanoparticles)SPCE/AGO-Cu(with an average size of 30 nm. At the SPCE surface, an oxidation peak was observed for Rohypnol at a potential of 0.30 V. However, an oxidation peak at a potential of 0.25 V with two reduction peaks were appeared for Rohypnol at the SPCE surface modified with AGO-Cu in the potential range of 0 to 1 V. The ability of the SPCE/AGO-Cu to measure Rohypnol was studied. A linear dependency was resulted between Rohypnol concentration and SPCE/AGO-Cu response in the range of 0.4�140 μM and a limit of detection (LOD) of 0.13 μM in aqueous solution. According to the results, the SPCE/AGO-Cu provides an accurate and precise assay pathway of Rohypnol in the fruit juice. © 2020 Elsevier B.V