Preparation and Investigation of Silver Nanoparticle–Antibody Bioconjugates for Electrochemical Immunoassay of Tick-Borne Encephalitis

A new simple electrochemical immunosensor approach for the determination of antibodies to tick-borne encephalitis virus (TBEV) in immunological products was developed and tested. The assay is performed by detecting the silver reduction signal in the bioconjugates with antibodies (Ab@AgNP). Here, signal is read by cathodic linear sweep voltammetry (CLSV) through the detection of silver chloride reduction on a gold–carbon composite electrode (GCCE). Covalent immobilization of the antigen on the electrode surface was performed after thiolation and glutarization of the GCCE. Specific attention has been paid to the selection of conditions for stabilizing both the silver nanoparticles and their Ab@AgNP. A simple flocculation test with NaCl was used to select the concentration of antibodies, and the additional stabilizer bovine serum albumin (BSA) was used for Ab@AgNP preparation. The antibodies to TBEV were quantified in the range from 50 IU·mL?1 to 1600 IU·mL?1, with a detection limit of 50 IU·mL?1. The coefficient of determination (r2) is 0.989. The electrochemical immunosensor was successfully applied to check the quality of immunological products containing IgG antibodies to TBEV. The present work paves the path for a novel method for monitoring TBEV in biological fluids

Capecitabine from X-ray powder synchrotron data

In the title compound [systematic name 5-de­oxy-5-fluoro-N-(pent­yloxycarbon­yl)cytidine], C15H22FN3O6, the pentyl chain is disordered over two positions with refined occupancies of 0.53 (5) and 0.47 (5). The furan ring assumes an envelope conformation. In the crystal, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into chains propagating along the b axis. The crystal packing exhibits electrostatic inter­actions between the 5-fluoro­pyrimidin-2(1H)-one fragments of neighbouring mol­ecules as indicated by short O⋯C [2.875 (3) and 2.961 (3) Å] and F⋯C [2.886 (3) Å] contacts

Biorelevant dissolution of candesartan cilexetil

The choice of an appropriate medium for dissolution tests is an essential step during a dosage form development. The adequate design of dissolution testing enables forecasting in vivo behavior of drug formulation. Biorelevant media were developed for this purpose because dissolution media described in the International Pharmacopoeia are not thoroughly suitable. Therefore, we carried out solubility and dissolution tests in biorelevant media and we compared the results with data measured in compendial dissolution media. A shake-flask method and standard paddle apparatus were used. The concentration was measured by a UV-Vis spectrophotometer. An oral solid dosage form with poorly soluble drug candesartan cilexetil was tested. Significant differences in the solubility and dissolution profiles of candesartan cilexetil were observed. The study offers the overview of compendial and biorelevant media simulating fasted state that can be analyzed by a spectrophotometric technique

Application of Combined Sorbent For Process of Water Purification From Microbial Contamination

The results of sorption efficiency of filter material which was obtained on the base of river sand and modified by aluminium oxyhydroxide with the sol-gel process are presented. All components were tested as sorbents, and their properties were compared. New filter material was found effective in the process of water treatment from bacterial contamination

Application of Combined Sorbent For Process of Water Purification From Microbial Contamination

The results of sorption efficiency of filter material which was obtained on the base of river sand and modified by aluminium oxyhydroxide with the sol-gel process are presented. All components were tested as sorbents, and their properties were compared. New filter material was found effective in the process of water treatment from bacterial contamination

Preparation and Investigation of Silver Nanoparticle–Antibody Bioconjugates for Electrochemical Immunoassay of Tick-Borne Encephalitis

A new simple electrochemical immunosensor approach for the determination of antibodies to tick-borne encephalitis virus (TBEV) in immunological products was developed and tested. The assay is performed by detecting the silver reduction signal in the bioconjugates with antibodies (Ab@AgNP). Here, signal is read by cathodic linear sweep voltammetry (CLSV) through the detection of silver chloride reduction on a gold−carbon composite electrode (GCCE). Covalent immobilization of the antigen on the electrode surface was performed after thiolation and glutarization of the GCCE. Specific attention has been paid to the selection of conditions for stabilizing both the silver nanoparticles and their Ab@AgNP. A simple flocculation test with NaCl was used to select the concentration of antibodies, and the additional stabilizer bovine serum albumin (BSA) was used for Ab@AgNP preparation. The antibodies to TBEV were quantified in the range from 50 IU·mL−1 to 1600 IU·mL−1, with a detection limit of 50 IU·mL−1. The coefficient of determination (r2) is 0.989. The electrochemical immunosensor was successfully applied to check the quality of immunological products containing IgG antibodies to TBEV. The present work paves the path for a novel method for monitoring TBEV in biological fluids