Square wave voltammetric determination of hydrazine and 4-chlorophenol as two important water pollutants using nanostructure-amplified sensor

A comprehensive exploration of tartrazine detection in food products: Leveraging fluorescence nanomaterials and electrochemical sensors: Recent progress and future trends

Azo dyes are widely used as food coloring agents because of their affordability and stability. Examples include brilliant blue, carmoisine, sunset yellow, allura red, and tartrazine (Tar), etc. Notably, Tar is often utilized in hazardous food goods. They are frequently flavoured and combined with food items, raising the likelihood and danger of exposure. Therefore, detecting Tar in food is crucial to prevent health risks. Fluorescence nanomaterials and electrochemical sensors, known for their high sensitivity, affordability, simplicity, and speed, have been widely adopted by researchers for Tar detection. This comprehensive paper delves into the detection of Tar in food products. It extensively covers the utilization of advanced carbon-based nanomaterials, including CDs, doped CDs, and functionalized CDs, for sensitive Tar detection. Additionally, the paper explores the application of electrochemical sensors. The paper concludes by addressing current challenges and prospects, emphasizing efforts to enhance sensitivity, and selectivity for improved food safety.

Development of a Highly Sensitive Electrochemical Sensor Using Sm2CuZrO6 Double Perovskite as an Electrocatalyst for Determination of Risperidone Antipsychotic Drug in Tablet Samples

In this study, the preparation of Sm2CuZrO6 double perovskites was carried out through the utilization of a sol-gel technique. The Sm2CuZrO6 displayed notable conductivity, impressive electrocatalytic activity, and rapid electron transfer. The monitoring of risperidone (RIS) in tablet samples is greatly influenced by these properties. Various techniques for structural and morphological characterization were employed to confirm the formation of Sm2CuZrO6. The electrochemical properties of Sm2CuZrO6 were assessed through utilization of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). Interestingly, the Sm2CuZrO6 exhibited a remarkable wide linear range of 50-500 nM, along with a detection limit of 10.62 nM. Notably, it demonstrated a sensitivity of 0.4038 μA μM-1 cm-2. The constructed sensor demonstrated noteworthy selectivity, stability, and repeatability. To assess the practicality of RIS, its performance was monitored in the tablet sample, resulting in satisfactory recoveries.

Incorporation of carbon black into a sonogel matrix: improving antifouling properties of a conducting polymer ceramic nanocomposite

A new electrochemical sensor device has been developed through the modification of a polyaniline-silicon oxide network with carbon black (CB). Enhanced electrical conductivity and antifouling properties have been achieved due to the integration of this cheap nanomaterial into the bulk of the sensor. The structure of the developed material was characterized using Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy techniques. Cyclic voltammetry was used to characterize electrochemically the Sonogel-Carbon/Carbon Black-PANI (SNG-C/CB-PANI) sensor device. In addition, differential pulse voltammetry was employed to evaluate the analytical response of the sensor towards sundry chlorophenols, common environmental hazards in aqueous ecosystems. The modified sensor material showed excellent antifouling properties, which led to a better electroanalytical performance than the one displayed with the bare sensor. Notably, a sensitivity of 5.48 × 10³ μA mM^-1 cm^-2 and a limit of detection of 0.83 μM were obtained in the determination of 4-chloro-3-methylphenol (PCMC) at a working potential of 0.78 V (vs. 3 M Ag/AgCl/KCl), along with proficient values of reproducibility and repeatability (relative standard deviation < 3%). Finally, the analysis of PCMC was carried out in multiple validated water samples using the synthesized SNG-C/CB-PANI sensor device, obtaining excellent results of recovery values (97-104%). The synergetic effect of polyaniline and carbon black leads to novel antifouling and electrocatalytic effects that improve the applicability of this sensor in sample analysis versus complex conventional devices.

Application of oxidized multi-walled carbon nanotubes and zeolite nanoparticles for simultaneous preconcentration of codeine and tramadol in saliva prior to HPLC determination

In this work, a dispersive micro-solid phase extraction technique along with high-performance liquid chromatography-UV detection was developed for simultaneous preconcentraion and determination of trace levels of codeine and tramadol in human saliva. This method is based on the adsorption of codeine and tramadol on a mixture of oxidized multi-walled carbon nanotubes and zeolite Y nanoparticles with 1:1 ratio as an efficient nanosorbent. Various analytical parameters influencing the adsorption step including the amount of adsorbent, the pH of the sample solution, the temperature, the stirring rate, the contact time of the sample solution, and the adsorption capacity were investigated. Based on the results, 10 mg adsorbent, sample solutions with pH = 7.6, temperature of 25 °C, stirring rate 750 rpm and contact time 15 min, in the adsorption step shows the best results for both drugs. Then the effective parameters on the analyte desorption stage such as the type of desorption solution, pH of the desorption solution, desorption time and desorption volume were investigated. Studies have shown that water/methanol (50:50 v/v) as desorption solution, pH = 2.0, desorption time of 5 min and desorption volume of 2 ml gives the best results.Chromatographic separation was performed on a RP-Shim-pack CLC-ODS-C18 column (250 mm × 4.6 mm, 5 µm) with isocratic mode. The mobile phase contained of acetonitrile:phosphate buffer (18:82, v/v) at pH = 4.5 and the flow rate was 1 ml.min^-1. The wavelength of UV detector was adjusted at 210 nm and 198 nm for codeine and tramadol, respectively.Under optimum conditions, the extraction efficiencies of 98.5% and 99.2% were achieved for codeine and tramadol respectively. Enrichment factor of 13, detection limit of 0.3 μg L^-1, relative standard deviation of 4.07 for codeine; and an enrichment factor of 15, a detection limit of 0.15 μg L^-1, and standard deviation of 2.06 for tramadol were calculated. The linear range of the procedure for each drug was 1.0 to 1000 μg L^-1. This method was successfully applied for the analysis of codeine and tramadol in saliva samples.

Engineering MOFs derived metal oxide nanohybrids: Towards electrochemical sensing of catechol in tea samples

In this work, we have successfully developed Cu-MOF/CuO/NiO nanocomposites (NCs) and employed as a novel electrochemical sensing platform in catechol (CC) detection. The Scanning electron microscopy (SEM) along Energy dispersive X-ray Analysis (EDX), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) are carried out to characterize the as-fabricated Cu-MOF/CuO/NiO NCs. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques have used to obtain oxidation peak currents of CC. Glassy carbon electrode (GCE) modified with Cu-MOF/CuO/NiO has exposed the superb EC properties representing low limit of detection (LOD) of 0.0078 µM (S/N = 3). To assess the practicability of Cu-MOF/CuO/NiO based sensing medium, it has been used to detect CC from two varieties of tea, namely black and green. Thus, we anticipate that this structural integration strategy possesses encouraging application potential in sensing podium and material synthesis.

A novel electrochemical epinine sensor using amplified CuO nanoparticles and an-hexyl-3-methylimidazolium hexafluorophosphate electrode

This study suggests a carbon paste electrode modified with CuO nanoparticles andn-hexyl-3-methylimidazolium hexafluorophosphate (CPE/CuO-NPs/HMIPF₆) as a powerful tool for the analysis of epinine for the first time.