Single Molecule Bionanophotonics (until July 2011)

The Single Molecule Bionanophotonics group devotes its research activities to the development and application of cutting-edge optical techniques for the study of biological processes at the single molecular level and on living cells. Thus we aim to develop fluorescence techniques that combine high spatial and temporal resolution for the dual goals of probing and manipulating biological function at the level of single molecules in their native environment: the living cell.

Nanoscale imaging on intact cell membranes is obtained using near-field optical microscopy (NSOM). We also generate strong nanoscale optical fields and superfocusing by fabrication of optical nano-antennas, tuned in resonance with the photon emitters. These nano-antenna probes scanned in controlled proximity to cell membranes allow optical resolution below 30nm. High temporal resolution is achieved using fluorescence correlation spectroscopy (FCS) and Epi/Total internal reflection fluorescence microscopy (TIRF) for single emitter tracking on living cells.

Our aim is to elucidate fundamental biological questions that have important implications for health and disease. Topics that attract our attention in the biological arena are cell membrane compartmentalization at the nanoscale, leukocyte adhesion mediated by integrin receptors and pathogen recognition by cells of the immune system.

As highlights of our achievements in 2011 we demonstrated the feasibility of fluorescence correlation spectroscopy (FCS) based on the nanometric illumination of near-field scanning optical microscopy (NSOM) probes on intact living cells (Biophys. J. (2011), 100, L08). NSOM-FCS applied to fluorescent lipid analogs allowed us to reveal details of the diffusion hidden by larger illumination areas. Moreover, the technique offers the unique advantages of evanescent axial illumination and straightforward implementation of multiple colour excitation. In collaboration with the group of Prof. F. Sanz we evaluated the potential of functional polyelectrolyte based nanoparticles as nanocarriers for lysosomal delivery of therapeutic proteins (Biomacromolecules (2011), 12, 2524). Using high-resolution fluorescence microscopy we characterized at the single particle level the binding, cellular uptake and successful delivery of these nanocarriers to lysosomal compartments.

The Single Molecule Bionanophotonics group left IBEC in July 2011 and now continues its work at the Institut de Ciències Fotòniques (ICFO).

EU-funded projects

Privately funded projects

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