The use of porphyrins in potentiometric sensors as ionophores

Double Type Detection of Triiodide and Iodide Ions Using a Manganese(III) Porphyrin as Sensitive Compound

A paramagnetic A3B-type Mn(III)-porphyrin was synthesized and characterized by physical-chemical methods (UV-Vis, FT-IR, 1H-NMR spectroscopy). The obtained compound was tested as a sensitive material for the spectrophotometric and potentiometric detection of iodine species. Using UV-Vis spectroscopy, the triiodide anions could be detected with high precision in the concentration interval of 1.02 × 10-5 to 2.3 × 10-5 M, with an LOD of 9.44 × 10-6 M. The PVC-based electrode using DOP as a plasticizer showed a sensitivity toward iodide in a wide concentration range of 1.0 × 10-5 to 1.0 × 10-1 M, with an LOD of 8.0 × 10-6 M. Both methods are simple, low-cost, and efficient for the detection of iodine species in synthetic samples and pharmaceuticals.

Entropy analysis of nickel(II) porphyrins network via curve fitting techniques

Nickel(II) porphyrins typically adopt a square planar coordination geometry, with the nickel atom located at the center of the porphyrin ring and the coordinating atoms arranged in a square plane. The additional atoms or groups coordinated to the nickel atom in nickel(II) porphyrins are called ligands. Porphyrins have been investigated as potential agents for imaging and treating cancer due to their ability to selectively bind to tumor cells and be used as sensors for a variety of analytes. Nickel(II) porphyrins are relatively stable compounds, with high thermal and chemical stability. They can be stored in a solid state or in solution without significant degradation. In this study, we compute several connectivity indices, such as general Randi'c, hyper Zagreb, and redefined Zagreb indices, based on the degrees of vertices of the chemical graph of nickel porphyrins. Then, we compute the entropy and heat of formation NiP production, among other physical parameters. Using MATLAB, we fit curves between various indices and the thermodynamic properties parameters, notably the heat of formation and entropy, using various linearity- and non-linearity-based approaches. The method's effectiveness is evaluated using [Formula: see text], the sum of squared errors, and root mean square error. We also provide visual representations of these indexes. These mathematical frameworks might offer a mechanism to investigate the thermodynamical characteristics of NiP's chemical structure under various circumstances, which will help us understand the connection between system dimensions and these metrics.

Rapid electrochemical sensor for uranium(vi) assessment in aqueous media

The significance of reliable monitoring of uranium levels in water recourses calls for the development of time-saving, robust, and accurate methods for its estimation. In this view, the current study describes the design and analytical parameters of a potentiometric membrane sensor for uranium(vi) ions. The sensor is based on a new Schiff base derivative, as an ionophore, that was synthesized and structurally characterized by elemental, FTIR, and ¹HNMR analyses. The impact of the membrane constituents was studied and the membrane composition of PVC (32.50) : o-NPOE (65.00) : ionophore (2.00) :  KTpClPB (0.50) (%, w/w) achieved the optimal performance. A Nernestian response was observed for uranium(vi) ions within the concentration range 1.00 × 10⁻⁶ to 1.00 × 10⁻¹ mol L⁻¹. The sensor revealed a low detection limit of 3.90 × 10⁻⁷ mol L⁻¹ with satisfactory reproducibility. Stable and reproducible potentials were obtained within a short time (9 s) over the pH range 2.10–4.21. The impact of possible competing ions was investigated and the selectivity coefficients revealed appropriate selectivity for uranium(vi) ions over various cations without significant interference. The sensor's performance was examined by determining the amount of uranium(vi) in water samples and the results showed no significant differences from those obtained by the ICP-OES method.

A new Schiff base was synthesized and applied as ionophore to construct potentiometric sensor for uranium(vi) determination.

Potentiometric urea biosensors

Excess nitrogen in the body is converted to urea in the liver, and urea is disposed as a waste product in urine. Urea concentration can change in body fluids such as blood due to the presence of certain disorders. Therefore, the determination of urea is of high importance in various areas including medical diagnosis, as well as food quality control and environmental monitoring. Potentiometric sensors have certain advantages over their alternatives, such as rapidity, portability, cost effectiveness, high sensitivity, easy operation and simple apparatus. Potentiometric urea biosensors based on enzyme urease have been developed using various materials including nanoparticles and films, and also using different methodologies. In this review, we covered potentiometric urea biosensors reported in the literature, and touched upon their certain structure characteristics and performance parameters including detection limit, working concentration range, response time and lifetime, all of which are of practical importance. Each potentiometric urea biosensor has its own advantages and drawbacks, thus the selection of appropriate method depends on the sample to be analyzed, its urea concentration range and other requirements of the particular application. Further research is needed in order to optimize the performance of these devices and to broaden their applicability.

Applications of Potentiometric Sensors for the Determination of Drug Molecules in Biological Samples

Potentiometry is extensively studied by researchers as one of the electrochemical methods due to its multiple advantages. Until today, thousands of potentiometric sensors have been developed and applied successfully in many fields such as medicine, environmental monitoring, agriculture, industry and pharmaceutical sciences. Clinical drug analyses and determination of drugs in biological samples are highly important from a medical point of view. These analyses are carried out using various analytical devices including potentiometric sensors. These potentiometric sensors are superior to other devices in terms of several performance parameters, and thus present a good alternative for researchers. Using potentiometric sensors, very successful results in the identification of drug molecules in body fluids have been obtained and reported in the literature up to now. In this study, we review potentiometry-based sensors developed for the determination of drug molecules in various biological samples such as blood serum and urine, and touch upon their performance features in these applications.