Rapid detection of foodborne contaminants using an Array Biosensor

Foodborne contaminants come in a variety of sizes ranging from simple chemical compounds to entire bacterial cells. Due to public health concerns, there is a current need in the food industry for a sensitive, specific and rapid method to monitor for the presence of these toxic species, either as a result of natural or deliberate contamination. The Array Biosensor developed at the NRL encompasses these qualities, including the ability to measure multiple analytes simultaneously on a single substrate. In this study, we demonstrate the Array Biosensor's ability to measure both large pathogens, such as the bacteria Campylobacter jejuni (C. jejuni), and small toxins, including the mycotoxins ochratoxin A, fumonisin B, aflatoxin B1 and deoxynivalenol. Sandwich immunoassays were used to measure C. jejuni in buffer and a number of food matrices, while competitive immunoassays, taking only 15 min, were developed for the simultaneous detection of multiple mycotoxins. The combination of sandwich and competitive immunoassay formats on a single substrate was demonstrated, allowing the simultaneous detection of both large (C. jejuni) and small (aflatoxin B1) food contaminants.