An electrochemical sensor based on carbon nanofiber and molecular imprinting strategy for dasatinib recognition.

Herein, we proposed a new approach to design a MIP-based electrochemical sensor with carbon nanofiber (CNF), which could improve its conductivities as well as electrode sensitivity and successful detection of dasatinib (DAS). CNFs are capable of forming high porosity with significant interconnected porous networks. The poly(2-hydroxyethyl-methacrylate-N-methacryloyl-L-tyrosine) (PHEMA-MATyr) copolymer was synthesized in the presence of both CNF and DAS by photopolymerization. After optimization of the parameters, the modified MIP-based electrochemical sensor demonstrated the ability to determine the DAS in the linear working range of 1.0 × 10-14-1.0 × 10-13 M for the standard solution and commercial serum samples with a LOD of 1.76 × 10-15 and 2.46 × 10-15, respectively. Good linearity for DAS was observed with correlation coefficients (r) of 0.996 and 0.997 for the standard solution and commercial serum samples, respectively. The recoveries of the DAS ranged from 99.45 % to 99.53 % for the tablet dosage form and commercial serum samples, with average relative standard deviations below 1.96 % in both cases. The proposed modified sensor demonstrated significant sensitivity and selectivity for the rapid determination of DAS in commercial serum samples and tablet form.

Development of etching paste for serial number restoration on aluminum engine block.

Engine numbers, which involve information regarding the engine type, production number, and year and place of manufacture, are used for identification purposes. Comprising of unique alphanumeric characters, the engine numbers are fully or partially obliterated especially in auto theft and smuggling cases to conceal the origin, identity, and owner of vehicles. The limitations of the current restoration techniques such as the difficulty of using chemical liquid etching in vertical sites, the restrictions of magnetic and optical methods, and the applicability of several techniques like electron backscatter diffraction only in the laboratory environment prompt the development of new techniques. In view of these limitations and the importance of restoring engine numbers in criminal investigations, this unique study aimed to develop an etching paste that would restore the effaced characters on a real aluminum alloy engine block. The characters which were cold-stamped on the engine block were milled at varying depths and restoration attempts were conducted using etching pastes formed with different chemicals and materials. The analyses indicate that the etching paste formed with 200 mg of perlite, 400 mg of iron powder, and 450 µL of 20 M NaOH provided restoration to a good extent. The prevention of over-etching through the controlling of the chemical reaction and the cost-effectiveness appears to be the advantages of this technique. The success of recovery on the real engine block, the facilitation of restoration on curved surfaces, and the chance of on-site usage will likely make the etching paste a widely used tool in serial number restoration.

The effects of four different solvent vapours on the restoration of obliterated stamp markings from five different wooden surfaces.

The stamp markings on wooden surfaces, which are placed on trees and products including antiques, indicate the status of trees and involve identifying data regarding the products. Such markings are obliterated either to facilitate illegal logging or to conceal product information. Despite the wide literature on the restoration of obliterated characters on metal and polymer surfaces, the recovery of defaced characters on wooden surfaces appears to be understudied. Several reference texts in the forensic marks' examination literature suggest that water, water vapor, and alkaline solutions are useful in restoring the abraded markings on the wood. Since there does not seem to be any experimental study proving such success, this study aimed to fill this gap. This study conducted experimental research by using water, ethanol, ammonia, and chloroform to recover the scraped characters on samples obtained from walnut, beech, spruce, oak, and cedar trees. The cold-stamped characters, which were defaced at varying depths, were restored using vapor and liquid phases of four solvents. While the vapor phases of water, ethanol, and ammonia yielded good outcomes on all types of wooden surfaces, the liquid phases did not seem to be useful in the revisualization process. The response of the vapors, which varied between 62 and 220 s, depended on the type of wood. The restoration technique developed in this research offers the possibility of on-site usage, easy application, utilization of low-cost solvents, rapid recovery, and effectiveness on various wooden surfaces. Overall, the restoration methodology used in this research appears to be fruitful in retrieving identifying information on wooden samples.

Magnetic diatomite for pesticide removal from aqueous solution via hydrophobic interactions.

Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4'-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption-desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory-Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations. Graphical Abstract.