Unit:
Department of ChemistryLibrary of the School of Science
Dissertation committee:
Αναστάσιος Οικονόμου, Καθηγητής, Τμήμα Αναλυτικής Χημείας, Ε.Κ.Π.Α.
Σωτήριος Κακαμπάκος, Ερευνητής Α’, Ε.Κ.Ε.Φ.Ε. «Δημόκριτος»
Παναγιώτα Πέτρου, Ερευνήτρια Α’, Ε.Κ.Ε.Φ.Ε. «Δημόκριτος»
Κωνσταντίνος Μισιακός, Ερευνητής Α’, Ε.Κ.Ε.Φ.Ε. «Δημόκριτος»
Ευάγγελος Μπακέας, Αναπληρωτής Καθηγητής, Τμήμα Αναλυτικής Χημείας, Ε.Κ.Π.Α.
Μαργαρίτα Χατζηχρηστίδη, Επίκουρη Καθηγήτρια, Τμήμα Βιομηχανικής Χημείας, Ε.Κ.Π.Α.
Χρήστος Κόκκινος, Επίκουρος Καθηγητής, Τμήμα Αναλυτικής Χημείας, Ε.Κ.Π.Α.
Original Title:
Ανάπτυξη οπτικών ανοσοαισθητήρων για την ταυτόχρονη ανίχνευση τοξικών ουσιών σε τρόφιμα
Translated title:
Development of optical immunosensors for the simultaneous determination of toxic substances in food
Summary:
In this thesis a label-free optical biosensor for the fast simultaneous determination of three mycotoxins, aflatoxin B1 (AFB1), fumonisin B1 (FB1) and deoxynivalenol (DON) and for the determination of ochratoxin A (OTA) in beer samples is presented.
The biosensor is based on an array of ten Mach-Zehnder interferometers (MZIs) monolithically integrated along with their respective broad-band silicon light sources onto a single chip (37mm2). Multi-analyte determination is accomplished by functionalizing the sensing arms of individual MZIs with mycotoxin-protein conjugates. Assay is performed by pumping over the chip mixtures of calibrators or samples with a mixture of specific monoclonal antibodies, followed by reaction with a secondary anti-mouse IgG antibody. An external miniaturized spectrometer was employed to continuously record the transmission spectra of each interferometer. Spectral shifts obtained due to immunoreactions were transformed to phase shifts through Discrete Fourier Transform.
The detection limits achieved for AFB1, FB1, DON and OTA were 0.8, 5.6, 20 and 2,0 ng/ml in beer, respectively, while the assay duration for AFB1, FB1, DON was 12 min and for OTA 50 min. Recovery values ranging from 85 to 116% were determined in beer samples spiked with known concentrations of the four mycotoxins. In addition, beers of different types and origin were analysed with the biosensor developed and the results were compared with those provided by established laboratory methods, further supporting the accuracy of the proposed device. The good analytical performance of the biosensor and the small size of the proposed chip provide for the development of a portable instrument for point-of-need determinations.
Main subject category:
Science
Keywords:
Aflatoxin B1, Fumonisin B1, Deoxynivalenol, Ochratoxin A, Monolithically integrated Mach-Zehnder interferometers, Beer
Number of index pages:
11
Number of references:
180
