Development of dual-channel surface plasmon resonance imaging system applied to living tumour cell analyses

Presented is homemade dual-channel surface plasmon resonance (SPR) imaging (SPRI) system enabling living cell analysis in various stimuli based on refractive index (RI) variations. The system was constructed with a laser source of 650 nm, a P-polariser, a glass prism, an objective lens, a CCD camera, a dual-channel gold sensor chip, a dual-channel PDMS flow cell and a mechanical scanning device. Living human type II alveolar epithelial cell line A549 cells were cultured on the surface of a gold sensor chip. Different solutions were loaded into two independently parallel flow channels to make comparison of the cells´ reaction results. Cells´ responses in both the testing and the reference channels with and without K⁺ stimuli were collected. Furthermore, the epidermal growth factor (EGF) was loaded to stimulate cells in the testing channel while a mixture of EGF and Iressa (ZD1839) were loaded in the reference channel. The SPR response signal was different from the two channels, which indicated that Iressa as an EGFR inhibitor effectively inhibited the signal transduction of the EGF and EGFR bonding process of A549 cells. The use of the dual-channel SPRI system to study the behaviour of living cells to stimuli is of great help in understanding the life activities of living cells.