Nanoscale Fluorescence Emitters

Abstract

This chapter provides comparative analysis of properties of different nanoscale materials to absorb and emit visual and near-IR light with the focus on their applications in sensing and imaging technologies. Nowadays we observe that in these applications the novel nanoscale fl uorescent materials appear in strong competition with traditional organic dyes. They demonstrate diverse photophysical behavior and allow obtaining diverse information when they are incorporated into sensor composites or form the images in biological systems. Among these nanoscale emitters are the structures formed of organic dyes or by these dyes incorporated into different types of polymers with the resulting dramatically increased brightness. Collective excitonic effects appear when the aromatic units are coupled in conjugated polymers. Nanoscale structures formed of inorganic carbon in the form of nanodiamonds, graphene and graphene oxide pieces and the so-called carbon dots joined quite recently the family of fl uorophores. Semiconductor quantum dots present a range of bright emitters covering whole visible and near-IR spectral range. Finally, the up-converting nanocrystals make possible visible emission with near-IR excitation. Here we overview the most important features of these nanoscale materials. The following Chap. 6 will be focused on functional nanocomposites that allow extending the useful properties of these basic components.