An electrochemical magneto biosensor for the rapid determination of biotin in food samples is reported. The affinity reaction was performed on streptavidin-modified magnetic microbeads as a solid support in a direct competitive format. The biotinylated horseradish peroxidase enzyme (biotin-HRP) competes with free biotin in the sample for the binding sites of streptavidin on the magnetic microbeads. The modified magnetic beads were then easily captured by a magneto graphite-epoxy composite electrode and the electrochemical signal was based on the enzymatic activity of the HRP enzyme under the addition of H(2)O(2) as the substrate and o-phenilendiamine as cosubstrate. The response was electrochemically detected by square wave voltammetry. The limit of detection was 8.4×10(-8) mol L(--1) of biotin (20 μg L(--1)) with a dynamic range from 0.94 to 2.4×10(-7) mol L(--1). Biotin-fortified commercial dietary supplement and infant formula samples were evaluated obtaining good performances in the results. Total time of analysis was 40 min per 20 assays.
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http://dx.doi.org/10.1016/j.talanta.2012.05.003 | DOI Listing |
Plant Physiol Biochem
December 2024
Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, China.
Anthocyanin is the primary color-developing component in the pericarp of the passion fruit. Although the pericarp of the passion fruit is anticipated to be a significant source of anthocyanin, however, information regarding anthocyanin biosynthesis in the passion fruit pericarp remains unexplored. Based on metabolomics analysis, a total of five anthocyanins were identified in the purple-skinned passion fruit pericarp, among which three anthocyanins, petunidin-3-O-arabinoside, geranylgeranyl-3,5-O-diglucoside, and petunidin-3-O-rutinoside, play key roles in the coloration of the passion fruit pericarp.
View Article and Find Full Text PDFBiosens Bioelectron
December 2024
Centre for Biomedicine, Hull York Medical School, University of Hull, Hull HU6 7RX, United Kingdom. Electronic address:
Early detection of hepatitis C virus (HCV) infection is crucial for eliminating this silent killer, especially in resource-limited settings. HCV core antigen (HCVcAg) represents a promising alternative to the current "gold standard" HCV RNA assays as an active viremia biomarker. Herein, a highly sensitive electrochemical magneto-immunosensor for the HCVcAg was developed.
View Article and Find Full Text PDFBiosensors (Basel)
December 2024
Department of Electrical-Electronics Engineering, Abdullah Gul University, Kayseri 38039, Türkiye.
detection suffers from slow analysis time and high costs, along with the need for specificity. While state-of-the-art electrochemical biosensors are cost-efficient and easy to implement, their sensitivity and analysis time still require improvement. In this work, we present a paper-based electrochemical biosensor utilizing magnetic core-shell FeO@CdSe/ZnS quantum dots (MQDs) to achieve fast detection, low cost, and high sensitivity.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
China Auto Information Technology Co., Ltd, Tianjin 300300, People's Republic of China.
ChemSusChem
December 2024
Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant, Apartat 99, E-03080, Alicante, Spain.
Recent years have witnessed an intense effort to unravel magnetic field effects in electrocatalysis, as they can enhance the performance of common electrocatalysts. Both experimental and theoretical studies have shown that magnetic fields may affect, among others, the macroscopic spin-orbital ordering, charge transport, bubble release, and electron transfer kinetics. This paper highlights Electrochemical Impedance Spectroscopy (EIS) as a tool to analyze and separate the effects of magnetic field on both the oxygen reduction and evolution reactions at cobalt iron oxide electrodes.
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