Facile immobilization of potassium-copper hexacyanoferrate nanoparticles using a room-temperature ionic liquid as an ionic binder and its application towards BHA determination

Fabrication of magnetite/GO/potassium copper hexacyanoferrate nanocomposite for removal of radioactive cesium ions

Metal hexacyanoferrates (MHCF) are a class of inorganic adsorbents used for wastewater management due to the presence of interstitial sites for capturing heavy metal ions. In present work, we are reporting the synthesis of magnetic nanocomposite of Fe3O4/graphene oxide/potassium copper hexacyanoferrate via wet chemical and coprecipitation approach. Potassium copper hexacyanoferrate (KCuHCF) and Graphene oxide (GO) both are marvelous adsorbents but their nano-size becomes a major obstacle in their separation process after the adsorption of the radionuclides. Thus, our synthesized nanocomposite Fe3O4/GO/KCuHCF enhances the recovery of KCuHCF even after radioactive Cs+ adsorption with adsorption capacity of 18 mg g-1 coinciding well with the Langmuir adsorption isotherm mechanism. The synthesized adsorbent is characterized thoroughly using UV-Visible spectroscopy, FT-IR, TGA, XPS, Raman spectroscopy, TEM-EDAX and XRD. This synthesized nanocomposite is used for the batch extraction of radioactive Cs+ from low level radioactive waste (LLW). The extraction kinetics followed pseudo-second-order kinetics mechanism.

Preparation and Characterization of Functionalized Surgical Meshes for Early Detection of Bacterial Infections

Isotactic polypropylene (i-PP) nonabsorbable surgical meshes are modified by incorporating a conducting polymer (CP) layer to detect the adhesion and growth of bacteria by sensing the oxidation of nicotinamide adenine dinucleotide (NADH), a metabolite produced by the respiration reactions of such microorganisms, to NAD+. A three-step process is used for such incorporation: (1) treat pristine meshes with low-pressure O2 plasma; (2) functionalize the surface with CP nanoparticles; and (3) coat with a homogeneous layer of electropolymerized CP using the nanoparticles introduced in (2) as polymerization nuclei. The modified meshes are stable and easy to handle and also show good electrochemical response. The detection by cyclic voltammetry of NADH within the interval of concentrations reported for bacterial cultures is demonstrated for the two modified meshes. Furthermore, Staphylococcus aureus and both biofilm-positive (B+) and biofilm-negative (B-) Escherichia coli cultures are used to prove real-time monitoring of NADH coming from aerobic respiration reactions. The proposed strategy, which offers a simple and innovative process for incorporating a sensor for the electrochemical detection of bacteria metabolism to currently existing surgical meshes, holds considerable promise for the future development of a new generation of smart biomedical devices to fight against post-operative bacterial infections.

Detection of Synthetic Antioxidants: What Factors Affect the Efficiency in the Chromatographic Analysis and in the Electrochemical Analysis?

Antioxidants are food additives largely employed to inhibit oxidative reactions in foodstuffs rich in oils and fat lipids, extending the shelf life of foodstuffs and inhibiting alterations in color, flavor, smell, and loss of nutritional value. However, various research has demonstrated that the inadequate use of synthetic antioxidants results in environmental and health problems due to the fact that some of these compounds present toxicity, and their presence in the human body, in high concentrations, is related to the development of some cancer types and other diseases. Therefore, the development of analytical methods for identifying and quantifying synthetic antioxidants in foodstuffs is fundamental to quality control and in ensuring consumer food safety. This review describes the recent chromatographic and electrochemical techniques used in the detection of synthetic phenolic antioxidants in foodstuffs, highlighting the main characteristics, advantages and disadvantages of these methods, and specific typical features, which include extraction methods for sample preparation and materials used in the working electrode construction, considering chromatographic and voltammetric methods, since these specific features influence the efficiency in the analysis.

Electrochemical sensor for determination of butylated hydroxyanisole (BHA) in food products using poly O-cresolphthalein complexone coated multiwalledcarbon nanotubes electrode

In this study, we have reported an electrochemical sensor for the determination of butylated hydroxyanisole (BHA) by electropolymerization of O-cresolphthalein complexone (OC) over the multiwalled carbon nanotubes (MWCNTs). In order to confirm the surface morphology, oxidation states, functional groups and charge transfer property of POC/MWCNTs electrode, the resulting POC film with MWCNTs electrode was characterized by spectroscopy, microscopy, and electrochemical techniques. The fabricated electrode was evaluated for its electrochemical performance in oxidation of BHA and the study showed that at POC/MWCNTs electrodes BHA oxidation occurred at 0.27 V. POC/MWCNTs electrode has shown a linear range for the detection of BHA from 0.33 µM to 110 µM with the detection limit of 0.11 µM (S/N = 3). Amperometric determination of BHA was also done using chronoamperometric techniques and the result was found to be linear. The real time analysis of sensors is also validated by analysing the packed potato chips samples.