Providing a fast, reliable, and sensitive alternative to methods of detecting and characterizing analytes in solution will be invaluable to the healthcare services. Currently, analysis techniques may take several weeks providing either qualitative (analyte make-up) or quantitative (concentration) information for a given sample. Here, we present a method to simultaneously acquire both, by utilizing the Kretschmann configuration and combining SERS and plasmonic spectroscopic techniques into a single unit. The proposed method is based on the use of a plasmonic substrate consisting of metallic nanoparticles on a film geometry.

Despite the fact that analyte manipulation can have great applications in different research fields, most techniques used for this still present some limitations. Plasmonic nanostructures can be used to try and overcome this, but they lack the ability to manipulate objects over long distances. In this paper we therefore present different geometries for Brownian ratchet devices that are able to not only optically trap, but also to manipulate over long distances, dielectric nanometer-sized beads by periodically modulating an external light source.

Several properties of the developed PTB7 nanoparticles will be discussed, including their size, stability, fluorescent properties and generation of reactive oxygen species. Some cellular assays employing our conjugated polymer nanoparticles will also be presented, to highlight the potential of these nanoparticles as a versatile photodynamic therapy platform.

In this talk I will discuss some of the research directions of my group in the area of biosensing. Specifically, I will discuss: the development of hybrid plasmonic substrates that can be implemented into the Krechmann configuration for simultaneous qualitative and quantitative detection of analytes; the use of combinatory techniques based on plasmonic structures that enable control of analyte motion and thus concentration of analytes in the sensing area; and finally, the development of a theranostic agent based on conjugated polymer nanoparticles.