Multitoxin biosensor–mass spectrometry analysis: a new approach for rapid, real-time, sensitive analysis of staphylococcal toxins in food

Biomolecular interaction analysis mass spectrometry (BIA–MS) was applied to detection of bacterial toxins in food samples. This two-step approach utilizes surface plasmon resonance (SPR) to detect the binding of the toxin(s) to antibodies immobilized on a surface of a sensor chip. SPR detection is then followed by identification of the bound toxin(s) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Staphylococcal enterotoxin B (SEB) was readily detected in milk and mushroom samples at levels of 1 ng/ml. In addition, non-specific binding of food components to the immobilized antibody and to the sensor chip surface was detected. To evaluate the applicability of BIA–MS in the analysis of materials containing multiple toxic components, sample containing both SEB and toxic-shock syndrome toxin-1 was analyzed. Both toxins were successfully and simultaneously detected through the utilization of multiaffinity sensor chip surfaces.