Detection of mycotoxins using imaging surface plasmon resonance (iSPR)

Authors: Maragos, Chris; HOSSAIN, ZAKIR - Orise Fellow

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Significant progress has been made in the development of biosensors that can be used to detect mycotoxins. One technology that has been extensively tested is surface plasmon resonance (SPR). In 2003 a multi-toxin method was reported that detected aflatoxin B1 (AFB1), zearalenone (ZEA), fumonisin B1 (FB1), and deoxynivalenol (DON) in four separate flow cells [1]. Despite this early promise, there were no further reports describing application of SPR to multi-mycotoxin detection in foodstuffs until Kadota et al. developed a method for the simultaneous detection of nivalenol (NIV) and DON [2]. Meneely et al. detected DON and HT-2/T-2 toxins in parallel channels [3]. The instruments used individual channels for each toxin, often with a reference channel to control for matrix effects. More recently, SPR has been combined with imaging technologies that allow multiple sites within a flow cell to be rapidly interrogated. The result is imaging SPR (iSPR), where assays are performed at multiple locations in arrays. The technique was applied to DON and ZEA in maize and wheat [4]. Recent modifications include using polymer “brushes” and secondary antibodies labeled with gold nanoparticles (AuNP) to improve sensitivity [5]. The “traditional” and iSPR techniques have also been compared for a set of six mycotoxins [6]. The detection ranges of DON, ZEA, T-2 toxin, and FB1 in assays using two chips in the more traditional format allowed measurement at the EU regulatory limits in barley. Also reported was the design of a prototype iSPR instrument that was portable but less sensitive. In our research we have been investigating the potential application of iSPR for the detection of DON, T-2 toxin, ZEA, and FB1 in wheat. The selection of appropriate pairs of antibodies and immobilized antigens are critical. While affinity of antibodies for immobilized antigens is essential, regeneration of the sensor surface requires antibodies that are not of such high affinity that they cannot be removed during the regeneration steps. Thus the development of sensitive assays requires antibodies with a balance of affinities for the toxins and the antigens. The practical aspects of sensor design and function will be discussed, in particular the effects of solvent and matrix upon assay performance. 1. van der Gaag et al., Food Control 14, 251-254 (2003). 2. Kadota, et al., Anal. Chim. Acta 673, 173-178 (2010). 3. Meneely, et al., World Mycotoxin J. 5, 117-126 (2012). 4. Dorokhin, et al. Anal. Bioanal. Chem. 400, 3005-3011 (2011). 5. Hu, et al., J. Colloid Interface Sci. 431, 71-76 (2014). 6. Joshi, et al., Analyst (DOI10.1039/c5an02512e)(2016).