Application of 3,3’,5,5’-Tetramethylbenzidine (TMB) in Amperometric Immunoassays for Mycotoxin Detection
- Electrochemical methods make great promise to meet the demand for user-friendly on-site devices for monitoring important parameters. Food industry often runs own lab procedures, e.g., for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with miniaturized technologies. Enzyme-linked immunosorbent assays, with photometric detection of the horseradish peroxidase (HRP) substrate 3,3’,5,5’-tetramethylbenzidine (TMB), form a good basis for sensitive detection. To provide a straight-forward approach for the miniaturization of the detection step, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry, it could be shown that TMB electrochemistry is strongly dependent on the pH and the electrode material. It was found that screen-printed gold electrodes and a very low pH value (pH 1) are well-suited to perform the electrochemical detection of TMB, due to the reversible character of the redox reaction under theseElectrochemical methods make great promise to meet the demand for user-friendly on-site devices for monitoring important parameters. Food industry often runs own lab procedures, e.g., for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with miniaturized technologies. Enzyme-linked immunosorbent assays, with photometric detection of the horseradish peroxidase (HRP) substrate 3,3’,5,5’-tetramethylbenzidine (TMB), form a good basis for sensitive detection. To provide a straight-forward approach for the miniaturization of the detection step, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry, it could be shown that TMB electrochemistry is strongly dependent on the pH and the electrode material. It was found that screen-printed gold electrodes and a very low pH value (pH 1) are well-suited to perform the electrochemical detection of TMB, due to the reversible character of the redox reaction under these conditions. Under these conditions, a good signal stability over several measuring cycles is achieved, providing the basis for analyzing multiple samples. In contrast to this, for carbon screen-printed electrodes, it was found that the signal response has changed after the electrochemical reaction with TMB at pH 1. At moderately acidic conditions (pH 4), neither with carbon nor with gold electrodes a reproducible electrochemical detection of TMB could be achieved. Based on these findings, we created a smartphone-based, electrochemical, immunomagnetic assay for the detection of ochratoxin A (OTA) and ergometrine in food samples. A competitive assay is performed on magnetic beads using HRP and TMB/H2O2 to generate the signal. Enzymatically oxidized TMB is quantified after addition of H2SO4 by amperometry with screen-printed gold electrodes in a custom-made wall-jet flow cell. The results are in good correlation with the established photometric detection method, providing a solid basis for sensing of further analytes in HRP-based assays using the newly developed miniaturized smartphone-based, electrochemical, immunomagnetic assay.…
Autor*innen: | Soraya RiedelORCiD |
---|---|
Koautor*innen: | Deniz Hülagü, Francesca Bennet, Peter Carl, Sabine Flemig, Thomas Schmid, Jörg Schenk, Vasile-Dan Hodoroaba, Rudolf Schneider |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2022 |
Organisationseinheit der BAM: | 1 Analytische Chemie; Referenzmaterialien |
1 Analytische Chemie; Referenzmaterialien / 1.3 Instrumentelle Analytik | |
1 Analytische Chemie; Referenzmaterialien / 1.8 Umweltanalytik | |
6 Materialchemie | |
6 Materialchemie / 6.1 Oberflächen- und Dünnschichtanalyse | |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | Amperometry; Cylic Voltammetry; Electrochemistry; Immunoassay; Mycotoxins |
Themenfelder/Aktivitätsfelder der BAM: | Umwelt |
Umwelt / Sensorik | |
Veranstaltung: | 73rd Annual Meeting of the ISE |
Veranstaltungsort: | Online meeting |
Beginndatum der Veranstaltung: | 12.09.2022 |
Enddatum der Veranstaltung: | 16.09.2022 |
Bemerkung: | Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 21.09.2022 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |