The electroanalytical determination of avidin in solution, in a carbon paste, and in a transgenic maize extract was performed in acidic medium at a carbon paste electrode (CPE). The oxidative voltammetric signal resulting from the presence of tyrosine and tryptophan in avidin was observed using square-wave voltammetry. The process could be used to determine avidin concentrations up to 3 fM (100 amol in 3 microl drop) in solution, 700 fM (174 fmol in 250 microl solution) in an avidin-modified electrode, and 174 nM in a maize seed extract. In the case of the avidin-modified CPE, several parameters were studied in order to optimize the measurements, such as electrode accumulation time, composition of the avidin-modified CPE, and the elution time of avidin. In addition, the avidin-modified electrode was used to detect biotin in solution (the detection limit was 7.6 pmol in a 6 mul drop) and to detect biotin in a pharmaceutical drug after various solvent extraction procedures. Comparable studies for the detection of biotin were developed using HPLC with diode array detection (HPLC-DAD) and flow injection analysis with electrochemical detection, which allowed biotin to be detected at levels as low as 614 pM and 6.6 nM, respectively. The effects of applied potential, acetonitrile content, and flow rate of the mobile phase on the FIA-ED signal were also studied.
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Anal Chim Acta
February 2025
Biofuel and Renewable Energy Research Center, Department of Biotechnology, Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
Background: The buildup of methylparaben (MP), a broad-spectrum antimicrobial preservative with endocrine-disrupting properties, in environmental sources, especially aquatic systems, has become a significant concern due to its adverse health effects, including allergic reactions, promoting the risk of developing cancer, and inducing reproductive disorders. Hence, introducing inexpensive and easy-to-use monitoring devices for rapid, selective, and sensitive detection and quantification of MP is highly desirable. In this context, electrochemical platforms have proven to be attractive options due to their remarkable features, such as ease of fabrication and use, short response time, and acceptable sensitivity, accuracy, and selectivity.
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January 2025
National Organization for Drug Control and Research (NODCAR), P.O.Box 29, Cairo, Egypt.
Tirofiban hydrochloride is used to inhibit platelet aggregation, which has a significant impact on the treatment of congestive heart failure the most common cause of death according to WHO. Therefore, its quantification in pharmaceutical dosage form is critical. In this work, an electrochemical method for the determination of tirofiban HCl in pharmaceutical dosage form was developed and validated.
View Article and Find Full Text PDFJ Mater Sci Mater Med
January 2025
Department of Chemistry, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran.
The antimalarial hydroxychloroquine (HCQ) has considered for the treatment of systemic lupus erythematosus. Moreover, HCQ has been used as a drug to treat Coronavirus disease (COVID-19). In this work, nitrogen doped porous reduced graphene oxide (NprGO) has been prepared via environmentally friendly process using Fummaria Parviflora extract.
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December 2024
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China.
Alite calcium sulfoaluminate (ACSA) cement is an innovative and environmentally friendly cement compared to ordinary Portland cement (OPC). The synthesis and hydration of ACSA clinkers doped with gradient sulfur were investigated. The clinker compositions and hydrated pastes were characterized by X-ray diffraction (XRD), isothermal calorimetry, mercury intrusion porosimetry (MIP), and scanning electron microscopy (SEM) to analyze its mineral contents, hydration products, heat release, pore structure, and microstructure.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Energy School, Xi'an University of Science and Technology, Xi'an 710054, China.
Fly ash-cement composite backfill slurry, prepared by partially replacing cement with fly ash, has been demonstrated to effectively reduce the mine backfill costs and carbon emissions associated with cement production. However, the use of fly ash often results in insufficient early and medium-term strength of the backfill material. To address the demand for high medium-term strength in backfill materials under continuous mining and backfilling conditions, this study developed a silica fume-fly ash-cement composite backfill slurry.
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