•Laser method for synthesis of bimetallic materials for enzyme-free microbiosensors.•Relationship between the structure of complexes and the properties of microbiosensors is shown.•The gap in ...knowledge about the structure of bimetal wine complexes has been filled.
The use of laser methods for synthesizing new materials for non-enzymatic electrochemical microsensors for express analysis of biological fluids is a promising scientific question.
Laser-induced chemical liquid phase deposition is the laser deposition of invisible miniature bimetallic deposits from aqueous solutions of salts and complexes of transition metals. Bimetallic complexes containing two transition metal cations in the shell of one ligand are of increased interest. There is an information gap in this area even for ligands such as tartrate. The studies carried out make it possible to obtain new information on the structure of bimetallic tartaric complexes in solutions containing simultaneously copper, nickel, silver, iron, and cobalt.
Various methods of synthesis of CuInSe
2
remain relevant because it is one of the most effective materials for solar energy. An effective method for the preparation of the CuInSe
2
nanodispersed ...selenium precursor for microwave synthesis is considered. Colloidal selenium solutions were obtained using laser ablation in various liquid media: water, ethanol, triethylene glycol, polyethylene glycol–400 (PEG-400), and a 1% solution of PEG-1500 in PEG-400. The optical properties of the obtained colloidal selenium solutions were studied. Electron microscopy of selenium particles was conducted. Trends of ablation rate change and physicochemical properties of dispersed selenium particles in the variety of liquid media listed above are discussed. The possibility of synthesizing CuInSe
2
using the obtained precursor was verified.
Laser-induced deposition of metals from a solution has been used as a new method for the synthesis of microcomposite materials in the copper-silver system. It was shown that the obtained materials ...have good sensory properties with respect to the determination of
d
-glucose in aqueous solutions. It is also shown that it can be used for gas sensors. Control of sensory properties can be done by changing the method of deposition. X-ray diffraction, EDX, and impedance spectroscopy were used to characterize the materials obtained and it was shown that laser sequential deposition and coprecipitation of two metals give different results. An explanation of the results was proposed. It explains them by the eutectic nature of the interaction in the copper-silver system.
•The possibility of using Raman spectroscopy for dating a document is shown.•A procedure for the mathematical processing of spectra for dating is proposed.•The choice of components of the PCA spectra ...is justified.•The most effective dating method is to represent the dating in coordinates PC3–PC5.
The use of spectral analysis methods to determine the age of writing inks is an important forensic task. However, the use of spectral data for this purpose has a number of limitations and difficulties. This paper considers the application of the Raman spectroscopy method to an urgent forensic task. The known mechanisms of dye degradation are analyzed; Raman bands are identified that are related to the age of the sample. In a sample of 5 randomly selected writing inks, temporary markers were identified. Narrow sections of Raman spectra containing characteristic lines were used for analysis. It was shown that processing narrow sections of the Raman spectra using the PCA chemometric method allowed the separation of writing inks into groups (clusters) corresponding to different creation intervals.
The development of an algorithm to automate the process of measuring the magnetic properties of macroscopic objects in motion is an important problem in various industries, especially in ferrous ...metallurgy and at factories where ferrous scrap is a strategic raw material. The parameter that requires work control is the hidden mass fraction of a non-magnetic substance that is present in the ferromagnetic raw material. The solution to this problem has no prototypes. In our work, a simple measuring device and a mathematical algorithm for calculating the mass fraction of the non-magnetic fraction in a strongly magnetic matrix were developed. The device is an inductance coil, in which the angle of the electromagnet losses is related to the mass of the magnetic material moving the coil. The magnitude of the instantaneous values of the lost angle integral was compared with the result of weighing the object on scales. This allowed us to calculate the proportion of the magnetic and non-magnetic fractions. The use of this prototype is herein illustrated. The experimental results of the determination of the magnetic-fractional composition depending on the mass of scrap metal and its bulk and the magnetic characteristics are presented.
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