Midinfrared surface-plasmon resonance: A novel biophysical tool for studying living cells

We discuss the surface-plasmon resonance (SPR) technique based on Fourier transform infrared (FTIR) spectrometry. We explore the potential of the infrared surface plasmon technique for biological studies in aqueous solutions and compare it with the conventional surface plasmon technique operating in the visible range. We demonstrate that the sensitivity of the SPR technique in the infrared range is not lower and in fact is even higher. We show several examples of applying FTIR-SPR for biological studies: (i) monitoring D-glucose concentration in solution and (ii) measuring D-glucose uptake by erythrocytes in suspension. We emphasize the advantages of infrared SPR for studying living cell cultures and show how this technique can be used for characterization of (i) cholesterol penetration into plasma membrane and (ii) transferrin-induced clathrin-mediated endocytosis.