Catalytic effect of potassium in Na 1−x K x CdPb 3 (PO 4 ) 3 to detect mercury (II) in fish and seawater using a carbon paste electrode

Recent trends on electrochemical determination of antibiotic Ciprofloxacin in biological fluids, pharmaceutical formulations, environmental resources and foodstuffs: Direct and indirect approaches

In the last few decades, pharmaceuticals, credited with saving millions of lives, have emerged as a new class of environmental contaminants. These compounds can have both chronic and acute harmful effects on aquatic ecosystems and consequently on human health. Therefore, there is an urgent need for the development of extremely sensitive, portable, and low-cost devices to perform analysis. In the present review article, recent reports on the application of various voltammetric and photo-electrochemical techniques using different electrode materials for the determination of antibiotic Ciprofloxacin (CIPRO) are reported. This review provides an insight into direct and indirect electrochemical approaches as well as the photoelectrochemical methods used for the determination of CIPRO. Emphasis is put on the applications of unmodified and modified carbon-based electrodes considering the modifier, supporting electrolytes, analytical method, concentration range, limit of detection, and real matrices. Carbon-based electrodes are the most used materials attributed to their commercial availability, reduced cost, high chemical stability, and non-toxicity.

Recent advances in electrochemical sensors for amoxicillin detection in biological and environmental samples

Amoxicillin (AMX) is among the most successful antibiotics used for human therapy. It is used extensively to prevent or treat bacterial infections in humans and animals. However, the widespread distribution and excess utilization of AMX can be an environmental and health risk due to the hazardous potential associated to its pharmaceutical industries effluents. Besides, their extensive use in food animal production may result in some undesirable residues in food, e.g. meat, eggs and milk. Consequently, at high enough concentrations in biological fluids, AMX may be responsible of various diseases such as nausea, vomiting, rashes, and antibiotic-associated colitis. For this reason, the detection and quantification of amoxicillin in pharmaceuticals, biological fluids, environmental samples and foodstuffs require new electroanalytical techniques with sensitive and rapid measurement abilities. This review discusses recent advances in the development of electrochemical sensors and bio-sensors for AMX analysis in complex matrices such as pharmaceuticals, biological fluids, environmental water and foodstuffs. The main electrochemical sensors used are based on chemically modified electrodes involving carbon materials and nanomaterials, nanoparticles, polymers and biological recognition molecules.

Elaboration, Rietveld Refinements and Vibrational Spectroscopic Studies of a new Lacunar Apatite Series: NaPb3-x CaxCd(PO4)3 (0 ≤ × ≤ 1)

The solid–solution series NaPb3-xCaxCd(PO4)3 (0 ≤ × ≤ 1) has been synthesised and crystallised in the hexagonal system with the P63/m space group. A refinement study using the Rietveld method shows good agreement between the observed and calculated patterns. The structure can be described as built up from [PO4]3- tetrahedra and Pb2+/Cd2+/Ca2+ of six-fold coordination cavities (6h positions), which delimit void hexagonal tunnels running along [001]. These tunnels are connected by cations of mixed sites (4f) which are half occupied by Pb2+/Cd2+/Ca2+ and half by Na+ cations. The vibrational spectra of all the compositions are similar and show some linear shifts as a function of the composition towards lower values due to the substitutions of Pb2+ by Ca2+ with a smaller radius.

Location and orientation of lone pairs in apatite-type materials: a computational study

Electron localisation function (ELF) calculations have been used to provide the first computational location of the cation lone pairs in apatite materials. We show that the orientation of the lone pairs varies depending on the identity and positions of the channel anions. The results represent a new platform for interpreting experimentally observed structure-property relationships in functional apatites. In particular, they have significant implications for ionic conductivity and suggest that structure-property relationships in lone-pair containing apatite-type solid electrolytes are more complex than previously thought.