Filtern
Dokumenttyp
- Zeitschriftenartikel (5)
- Vortrag (3)
- Posterpräsentation (2)
Schlagworte
- Ochratoxin A (10) (entfernen)
Organisationseinheit der BAM
Eingeladener Vortrag
- nein (3)
Electrochemical methods offer great promise in meeting the demand for user-friendly on-site devices for Monitoring important parameters. The food industry often runs own lab procedures, for example, for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with smart technologies. Enzyme-linked immunosorbent assays, with photometric detection of 3,3’,5,5’-tetramethylbenzidine (TMB),form a good basis for sensitive detection. To provide a straightforward approach for the miniaturization of the detectionstep, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry it was found that the TMB electrochemistry is strongly dependent on the pH and the electrode material. A stable electrode response to TMB could be achieved at pH 1 on gold electrodes. We created a smartphonebased, electrochemical, immunomagnetic assay for the detection of ochratoxin A in real samples, providing a solid basis forsensing of further analytes.
How to trace the "cereal" killer? Fungal secondary metabolites, aka mycotoxins, pose a severe health risk for humans and animals. Since their occurrence in food, such as cereal products, is inevitable, the detection is of considerable importance. I want to demonstrate how the trace analysis of mycotoxins in foodstuff can be performed outside the laboratory. For this purpose, sensitive, antibody-based methods are combined with electrochemical smartphone-based detection.
Immunomagnetic ochratoxin a assay with electrochemical 3,3′,5,5′ tetramethylbenzidine detection
(2021)
The demand for miniaturized analytical devices monitoring important parameters in the food and medical industry has increased strongly in the past decades. With fast progress, smart technologies are finding their way into our everyday life. For the future, it is, therefore, a major goal to also link analytical methods with smart technologies to create user-friendly on-site devices. In food industry the monitoring of harmful substances such as dioxins, heavy metals or mycotoxins plays a key role, since the European Commission prescribes legal limits for various food products and beverages[1]. Therefore, companies often have their own laboratories and trained personnel. For one of the most abundant and toxic mycotoxins, Ochratoxin A (OTA) we want to present an electrochemical detection system in which the read-out can be performed with a smartphone connected via Bluetooth to a miniaturized potentiostat. The recognition of OTA is performed with specific antibodies in a competitive assay format. Anti-OTA-antibodies were captured on magnetic beads on which the competitive binding between OTA and an OTA horseradish peroxidase (HRP) tracer was performed. To quantify OTA, the enzymatic reaction of the tracer with 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2 is employed. Oxidized TMB, which is enzymatically produced by the reduction of H2O2, is quantified by amperometry with screen-printed electrodes in a custom-made flow system. The results of the electrochemical detection method are in good correlation with the photometric detection of TMB. To demonstrate the applicability, we tested our system with OTA-spiked beer and performed the measurement via smartphone.
The demand for miniaturized analytical devices monitoring important parameters in the food and medical industry has increased strongly in the past decades. With fast progress, smart technologies are finding their way into our everyday life. For the future, it is, therefore, a major goal to also link analytical methods with smart technologies to create user-friendly on-site devices. In food industry the monitoring of harmful substances such as dioxins, heavy metals or mycotoxins plays a key role, since the European Commission prescribes legal limits for various food products and beverages[1]. Therefore, companies often have their own laboratories and trained personnel. For one of the most abundant and toxic mycotoxins, Ochratoxin A (OTA) we want to present an electrochemical detection system in which the read-out can be performed with a smartphone connected via Bluetooth to a miniaturized potentiostat. The recognition of OTA is performed with specific antibodies in a competitive assay format. Anti-OTA-antibodies were captured on magnetic beads on which the competitive binding between OTA and an OTA horseradish peroxidase (HRP) tracer was performed. To quantify OTA, the enzymatic reaction of the tracer with 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2 is employed. Oxidized TMB, which is enzymatically produced by the reduction of H2O2, is quantified by amperometry with screen-printed electrodes in a custom-made flow system. Since it is well-known that oxidized TMB can precipitate on electrode surfaces[2], we have studied pitfalls of the electrochemical detection of TMB. By cyclic voltammetry we have compared the stability of the electrochemistry of TMB at different electrode materials (gold and carbon) and pH values (pH 1 and pH 4). It was found that a stable response of the electrode could be achieved at pH 1 on gold electrodes. Thus, we applied these reaction conditions for amperometric detection of TMB in the OTA assay. The results of the electrochemical detection method are in good correlation with the photometric detection of TMB. To demonstrate the applicability, we tested our system with OTA-spiked beer and performed the measurement via smartphone.
The demand for miniaturized analytical devices monitoring important parameters in the food and medical industry has increased strongly in the past decades. With fast progress, smart technologies are finding their way into our everyday life. For the future, it is, therefore, a major goal to also link analytical methods with smart technologies to create user-friendly on-site devices. In food industry the monitoring of harmful substances such as dioxins, heavy metals or mycotoxins plays a key role, since the European Commission prescribes legal limits for various food products and beverages. Therefore, companies often have their own laboratories and trained personnel. For one of the most abundant and toxic mycotoxins, Ochratoxin A (OTA) we want to present an electrochemical detection system in which the read-out can be performed with a smartphone connected via Bluetooth to a miniaturized potentiostat. The recognition of OTA is performed with specific antibodies in a competitive assay format. Anti-OTA-antibodies were captured on magnetic beads on which the competitive binding between OTA and an OTA horseradish peroxidase (HRP) tracer was performed. To quantify OTA, the enzymatic reaction of the tracer with 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2 is employed. Oxidized TMB, which is enzymatically produced by the reduction of H2O2, is quantified by amperometry with screen-printed electrodes in a custom-made flow system. Since it is well-known that oxidized TMB can precipitate on electrode surfaces, we have studied pitfalls of the electrochemical detection of TMB. By cyclic voltammetry we have compared the stability of the electrochemistry of TMB at different electrode materials (gold and carbon) and pH values (pH 1 and pH 4). It was found that a stable response of the electrode could be achieved at pH 1 on gold electrodes. Thus, we applied these reaction conditions for amperometric detection of TMB in the OTA assay. The results of the electrochemical detection method are in good correlation with the photometric detection of TMB. To demonstrate the applicability, we tested our system with OTA-spiked beer and performed the measurement via smartphone.
Toxic secondary metabolites produced by fungi (aka mycotoxins) are often identified as contaminants in cereals or other food and pose a severe health risk, since they can be carcinogenic, neurotoxic, mutagenic or harmful in other respect. The highly nephrotoxic ochratoxin A (OTA) is one of the most important and widespread mycotoxins found in grains such as rye, wheat or oats. Thus, the fast and cost-effective detection of OTA is of great importance, to ensure that the toxin concentration is below the legal limits. Currently, the mycotoxin detection in mill operations is typically performed by means of the antibody-based ELISA method, which requires extensive laboratory equipment and specialized personnel. It was the aim of this study to develop an ELISA-inspired sensor method enabling the on-site quantification of OTA. Based on a classical competitive ELISA, an electrochemical detection system was developed. Anti-OTA-antibodies were captured on magnetic beads on which the competitive affinity reaction between OTA and an OTA- horseradish peroxidase (HRP) tracer was performed. Here the OTA concentration is inversely proportional to the amount of the bound OTA-HRP tracer, which was electrochemically quantified. For this purpose, oxidized tetramethylbenzidine (TMB), which is enzymatically produced by the reduction of H2O2 by the OTA-HRP tracer, is quantified by amperometry with screen-printed electrodes in a flow system. With this method a detection limit of 250 ng L-1 could be achieved which meets the current requirements for the detection of OTA in food and feed.
Die zuverlässige Überwachung geltender Mykotoxin-Grenzwerte ist elementarer Bestandteil von Lebensmittelsicherheit und Verbraucherschutz. Durch die zunehmende Bedeutung der Qualitätssicherung ist auch die Nachfrage an zertifizierten Referenzmaterialien (ZRM) in den letzten Jahren deutlich gestiegen. Dem steht derzeit jedoch nur eine sehr begrenzte Auswahl geeigneter ZRM gegenüber.
Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceus and Penicillium verrucosum. It has been found and analysed in several foods and feeds. Owing to its toxicity and occurrence in food and feed, the European Community has issued directives and some countries have their own regulations for OTA contents in food, feed and beverages. This work describes a method for the determination of OTA in mulled and red wine. It is based on combined anion exchange/reversed-phase clean-up and was analysed by liquid chromatography coupled with tandem mass spectrometry (multiple reaction monitoring). The method was validated with natural contaminated and spiked wine samples with OTA contents from 1.34 to 3.48 g kg1. Owing to its accuracy, good reproducibility and repeatability, this easy method is a good alternative to liquid chromatographyfluorescence detection methods.