Biotin determination in food supplements by an electrochemical magneto biosensor

• Published in: Talanta (Oxford) Vol. 97; pp. 484 - 490
• Main Authors: Kergaravat, Silvina V., Gómez, Gabriel A., Fabiano, Silvia N., Laube Chávez, Tamara I., Pividori, María I., Hernández, Silvia R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-08-2012; Elsevier
• Subjects: Analytic Sample Preparation Methods; Analytical chemistry; Biological and medical sciences; Biosensing Techniques - methods; Biosensors; Biotechnology; Biotin; Biotin - analysis; Biotin - isolation & purification; Calibration; Chemistry; Competitive assay; Dietary Supplements - analysis; Electrochemical magneto biosensor; Electrochemical methods; Electrochemistry; Exact sciences and technology; Food Analysis; Food samples; Fundamental and applied biological sciences. Psychology; General, instrumentation; Infant Formula - chemistry; Magnetic beads; Magnets - chemistry; Methods. Procedures. Technologies; Microspheres; Various methods and equipments; Magnetic beads; Biotin; Food samples; Electrochemical magneto biosensor; Competitive assay; Performance evaluation; Chemical analysis; Support; Electrochemical method; Voltammetry; Binding site; Signal; Enzymatic activity; Dynamics; Detection limit; Peroxidase; Infant formula; Time analysis; Enzyme; Sample; Foodstuff; Chemical sensor; Substrate; Peroxidases; Biosensor; Graphite; Affinity; Oxidoreductases; Square wave
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2012.05.003

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 H2O2 as the substrate and o-phenilendiamine as cosubstrate. The response was electrochemically detected by square wave voltammetry. The limit of detection was 8.4×10−8molL−−1 of biotin (20μgL−−1) with a dynamic range from 0.94 to 2.4×10−7molL−−1. Biotin-fortified commercial dietary supplement and infant formula samples were evaluated obtaining good performances in the results. Total time of analysis was 40min per 20 assays.
► Horseradish peroxidase activity was related to biotin amount. ► The response was obtained by square wave voltammetry. ► Magnetic beads modified with streptavidin were used and captured by a magneto electrode. ► Biotin-fortified real samples were analyzed by electrochemical magneto sensor.