Living cell-based allergen sensing using a high resolution two-dimensional surface plasmon resonance imager

Recently, several papers indicated that the surface plasmon resonance (SPR) technique was available to monitor stimulation responses of mammalian cells adhered on sensor chips. On the other hand, the newly developed two-dimensional SPR (2D-SPR) imager system can obtain 2D-images of local refractive index change on the surface of a gold thin film. From these backgrounds, we expected that the 2D-SPR imager can visualize the individual response of many mammalian cells, simultaneously. Here, we report the observation of an allergenic response of a model mast cell, rat basophilic leukaemia cell (RBL-2H3), by using the high magnification 2D-SPR imaging system after pre-sensitization with 0.1 μg mL(-1) anti-dinitrophenyl immunoglobulin E (anti-DNP IgE). The response of the cells was successfully observed as the increment of the SPR signal (reflection intensity) upon stimulation with 0.1-1000 ng mL(-1) DNP-modified bovine serum albumin (DNP-BSA).