Label-Free QCM Immunosensor for the Detection of Ochratoxin A

• Published in: Sensors (Basel, Switzerland) Vol. 18; no. 4; p. 1161
• Main Authors: Pirinçci, Şerife, Ertekin, Özlem, Laguna, Duygu, Özen, Fehime, Öztürk, Zafer, Öztürk, Selma
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.04.2018; MDPI
• Subjects: immobilization; immunobiosensor; Ochratoxin A; OTA; QCM; quartz crystal microbalance; regeneration; Sensors; immobilization; immunobiosensor; regeneration; quartz crystal microbalance; QCM; OTA; Ochratoxin A
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s18041161

Ochratoxin A (OTA) is a potent mycotoxin that poses a risk in food and feed moieties and subject to worldwide regulation. Laboratory-based analytical methods are traditionally employed for reliable OTA quantification, but these methods cannot provide rapid and on-site analysis, where biosensors fill this gap. In this study a label-free quartz crystal microbalance (QCM)-based immunosensor for the detection of OTA, which is one of the most important small molecule contaminants, was developed by direct immobilization of OTA to amine-bearing sensor surfaces using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) chemistry. The protein-free sensor surface enabled regeneration of sensor surface with 50 mM NaOH and 1% SDS up to 13 times without loss of performance, which would disrupt a protein-containing sensor surface. We developed a QCM immunosensor using the developed sensor surface with a 17.2–200 ng/mL detection range which can be used for on-site detection of feedstuffs.