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Submitted to: UJNR Food & Agricultural Panel Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 12/24/2015 Publication Date: 1/24/2016 Citation: Maragos, C.M. 2016. Multiplexed biosensors for detection of mycotoxins. UJNR Food & Agricultural Panel Abstracts. Interpretive Summary: Technical Abstract: As analytical methods have improved it has become apparent that mycotoxins exist in many forms within a commodity or food. For the established toxins there has been increased interest in the presence of metabolites that might also harbor toxicity. These include biosynthetic precursors as well as products from metabolism of the toxins themselves. “Masked” mycotoxins are those that have been metabolized by plants to forms that have generally not been detected by most analytical techniques. These include many products such as glucosides or glucuronides. In addition, there are compounds regarded as possible “emerging” toxins: secondary metabolites that are known to be toxic but which have not yet been associated with a known problem in humans or domestic animals. The desire to monitor for an increasing number of compounds (masked mycotoxins, emerging toxins) is met with the reality of limited resources for such monitoring. The need to detect more compounds with fewer resources has driven the development of progressively more sophisticated tools for detection. These have included novel mass spectrometric methods and immunoassays. Immunoassays are established, practical, tools used worldwide for monitoring natural toxins in commodities and foods. Immunoassays have a unique position in the analysis of small toxins, because the antibodies upon which they are based have excellent selectivity for the target toxin but may also have cross-reactivity to related toxins. Many of today’s immunoassays are in the format of biosensors that are amenable to performing multiplexed detection. A significant advantage of multiplexed sensors is the capacity to detect multiple toxins simultaneous, improving sample throughput. Multiplexed biosensors can be categorized based upon the type of label that is used for detection, which is selected to integrate with the detection technology used. Broadly, the biosensors are grouped into those that use enzymatic labels, non-enzymatic labels, or no label (i.e. label free). The former include enzyme linked immunosorbent (ELISA)-type assays with various endpoints (color, fluorescence, electrochemical, etc.). The non-enzymatic assays typically use highly colored or fluorescent labels (colloidal gold, quantum dots, etc.), while the label-free technologies measure the binding interaction in ‘real time’ (using surface plasmon resonance, biolayer interferometry, etc.). The potential issues with multiplexed biosensors include susceptibility to most of the common issues of immunoassays (matrix effects, cross-reactivity, etc.). There may also be additional issues related to the specific sensor formats, such as regeneration of the sensor surface. Despite these issues, the potential for multiplexed sensors is excellent, as the platforms are becoming increasingly amenable to commercialization and, therefore, more widespread use. |
