Electrochemical Monitoring of Methotrexate Anticancer Drug in Human Blood Serum by Using in situ Solvothermal Synthesized Fe3O4/ITO Electrode

Here, we reported on a one‐step fabrication of magnetite Fe₃O₄ nanoparticles/indium tin oxide (ITO) electrode based on the direct growing of Fe₃O₄ nanoparticles on the ITO surface by using a solvothermal process. The modified electrode was used as electrochemical methotrexate (MTX) biosensor with high sensitivity based on cyclic voltammetry and square wave voltammetry techniques. The results demonstrated a linear relationship between the MTX concentration and its oxidation current peak over a wide range from 10^?5 to 10^?14 mole/L with a limit of detection of 0.4×10^?15 M based on the square wave voltammetry (SWV) technique. In addition, Fe₃O₄/ITO electrode showed a good capability for measuring very low concentrations of MTX drug dissolved in human serum solution. Also, Fe₃O₄/ITO electrode was used for detecting MTX in blood serum samples collected from patients after their treatment with MTX. The prepared electrode showed the higher sensitivity that higher than the Viva‐E instrument, which opens the door for developing a cheap, simple and higher sensitive MTX sensor.     

Host–Guest Chemistry Within Cellulose Nanocrystal Gel Receptors

Cellulose nanocrystals (CNCs) spontaneously assemble into gels when mixed with a polyionic organic or inorganic salt. Here, we have used this ion-induced gelation strategy to create functional CNC gels with a rigid tetracationic macrocycle, cyclobis(paraquat-p-phenylene) ( CBPQT ⁴⁺). Addition of [ CBPQT ]Cl₄ to CNCs causes gelation and embeds an active host inside the material. The fabricated CNC gels can reversibly absorb guest molecules from solution then undergo molecular recognition processes that create colorful host–guest complexes. These materials have been implemented in gel chromatography (for guest exchange and separation), and as elements to encode 2- and 3-dimensional patterns. We anticipate that this concept might be extended to design a set of responsive and selective gel-like materials functioning as, for instance, water-pollutant scavengers, substrates for chiral separations, or molecular flasks.     

Densitometric Kinetic Stability Studies of Some Plant Extracts Using Different Regression Methods

JPC – Journal of Planar Chromatography – Modern TLC -     

Biometric identification using local iterated function

Biometric identification protocol has been received an increasing interest recently. It is a process that determines person identity by making use of their biometric features. A new biometric identification method is presented in this paper based on partial self-similarity that used to identify features within fingerprint images. This approach is already used in Fractal Image Compression (FIC) due to their ability to represent the images by a limited number of affine transformations, and its variation of scale, translation or rotation. These features give the recognition process high impact and good performance. To process data in a fingerprint image, it first converted into digital format using Optical Fingerprint Reader (OFR). The verification process is done by comparing these data with the server data. The system analysis shows that the proposed method is efficient in terms of memory and time complexity.     

A novel route to prepare highly surface active nanogel particles based on nonaqueous emulsion polymerization

The motivation of the current work has stemmed from the fact that the selection of suitable stabilizers for nonaqueous emulsions is still challenging because of lack of general knowledge about the underlying stabilization mechanisms. The preparation and surface activity of new amphiphilic gel nanoparticles in organic solvents were investigated. A new bifunctional surfmer was prepared by reacting polyoxyethylene 4‐nonyl‐2‐propylene‐phenol nonionic reactive surfactant with maleic anhydride followed by esterification with poly(ethylene glycol). This surfmer was used as stabilizer to prepare amphiphilic crosslinked N‐isopropylacrylamide (NIPAm) and 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) copolymer nanogel on the basis of nonaqueous radical copolymerization temperature modified method in the presence of toluene and formamide (FA) as solvents and N, N‐methylene bisacrylamide as a crosslinker. The chemical structure of the prepared nanogels was determined by Fourier transform infrared spectroscopy analyses. The morphologies of the prepared nanogels were detected by transmission electron microscopy and scanning electron microscopy techniques. The surface tension of colloidal NIPAm/AMPS dispersions was measured in FA as functions of surface age (time), temperature, and the morphology of the NIPAm/AMPS nanogels. The NIPAm/AMPS nanogels reduced the surface tension of FA from 58.2 to about 30.2 mN/m at 25°C, and a little increase in the surface tension was observed at 40°C. The prepared nanogels show great reduction in interfacial tension values between FA and styrene. The NIPAm/AMPS dispersions exhibited high surface activity and used as stabilizers to prepare crosslinked styrene‐co‐AMPS microgel in the presence of divinylbenzene and FA as organic solvents based on nonaqueous emulsion crosslinking polymerization technique. Copyright © 2013 John Wiley & Sons, Ltd.