A surface plasmon resonance imaging system for the stimulated living cell analysis

In this paper, a surface plasmon resonance imaging (SPRI) system for cell analysis is developed for obtaining the surface plasmon resonance (SPR) signal from the interactions between cells and different stimuli. The system is constructed with a red laser light source, a P-polarizer, a glass prism, a 5× objective lens, a charge coupled device (CCD) camera, a gold sensor chip, a polydimethylsiloxane (PDMS) reaction well and a mechanical scanning device. The system is applied to mapping living cells in response to stimuli by characterization of the refractive index (RI) changes. Cell responses to K+ in KCl solutions with concentrations of 5 mmol/L, 20 mmol/L, 50 mmol/L and 100 mmol/L are collected, which indicates that the SPRI method can distinguish the concentration of the stimuli. Furthermore, cell responses to epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) are studied independently. The binding of EGF receptor (EGFR) and EGF is collected as the first signal, and the internal change in cells is recorded as the second signal. The cell response to VEGF is different from that to EGF, which indicates that the SPRI as a label-free, real-time, fast and quantitative method has a potential to distinguish the cell responses to different stimuli.