Gold-Nanoparticle-Based Multiplexed Immunochromatographic Strip for Simultaneous Detection of Staphylococcal Enterotoxin A, B, C, D, and E

Staphylococcal enterotoxins (SEs) in food samples can cause severe gastroenteritis even at low doses. Detection of SEs with a single assay would not only improve reliability and portability, but would also save time. In this paper, for the first time, a multiplexed gold-nanoparticle-based immunochromatographic (ICT) strip that allows the simultaneous detection of the five main SEs has been reported: SEA, SEB, SEC, SED, and SEE. Based on the sandwich immunoassay of each SE, a multiplexed ICT strip with five test lines is developed. Sensitive and specific paired monoclonal antibodies facilitate the detection, allowing for high sensitivity and good specificity. The portable biosensor platform can simultaneously detect SEA, SEB, SEC, SED, and SEE at concentrations as low as 2.5, 2.5, 2.5, 1, and 5 ng mL(-1), respectively. The entire test can be performed within 15 min and requires no sophisticated instruments except a portable strip reader. To evaluate the multiplexed strip, naturally SEA and SEC contaminated milk samples and pure milk samples spiked with the five SEs are analyzed.