Development of a multiplex biosensor for the detection of mycotoxins

  • Philana Nolan

Student thesis: Masters ThesisMaster of Philosophy

Abstract

Mycotoxins produced by Fusarium species including trichothecenes, zearalenone and fumonisins, co-contaminate food and feed throughout the supply chain, including maize, cereal grains and animal feeds. There is an increasing demand to enhance global food security by improving the monitoring of mycotoxins throughout our food supply chain. For time and cost-efficient analysis, rapid tests capable of detecting multiple toxins from a single sample are ideal. Considering these current trends in mycotoxin testing, this project examined the feasibility of using both a portable and non-portable mass-based biosensor for multiplex mycotoxin detection. The biosensor was a mass sensitive microarray (MSMA) which consisted of 4 x 16 miniaturized mass sensitive transducer pixels based on solidly mounted resonator (SMR) technology. Functionalisation of individual pixels on the sensor surface using nano-spotting technology for the simultaneous and semi-quantitative detection of three regulated mycotoxins: T2-toxin (T2) zearalenone (ZEN), and fumonisin B1 (FumBl) was examined. With the integration of portable and non-portable microfluidic devices for antibody and standard sample injections, competitive inhibition assays were developed followed by single-plex and multiplex calibration curves. The characteristics and performance of the MSMA were evaluated including sensitivity which was determined as the concentration causing 50% inhibition. Sensitivity of single plex assays using the portable microfluidic device (PMD) were 1.32ng/ml, 2.00ng/ml and 6.84ng/ml forT2, FumBl and ZEN, respectively. Sensitivity of the multiplex assay again using the PMD was 6.09ng/ml, 3.57ng/ml and 2.41ng/ml for T2, FumBl and ZEN, respectively. All IC50 values obtained in assays conducted with the PMD and NPMD are considerably below all maximum levels (ML's) forT2, ZEN and FumBl in food and feed enforced in the European Union through Regulation (EC) No 1881/2006, 401/2006 and 519/2014. The PMD was an easy to use and highly sensitive screening tool which has been demonstrated for the multiplex detection of three regulated mycotoxins. Analysis was in real time and results were fully digital. Since detection of analytes was by mass it was both a label-free and cost-efficient method of analysis for mycotoxins.
Date of AwardDec 2019
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorKatrina Campbell (Supervisor) & Christopher Elliott (Supervisor)

Keywords

  • mycotoxin;
  • immunoassay
  • biosensor
  • on-site detection
  • rapid detection method
  • multiplex detection

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