Optical properties and applications of dendrimer-metal nanocomposites

The use of novel nanostructured materials for optical applications continues to be an important issue for the creation of new devices. New materials including metal nanoparticles have played an important role for applications in photonics, biology, as well as medicine. This review primarily concerns the use of one particular metal nanoparticle topology, dendrimer - metal nanocomposites. The focus of this review is to describe the optical properties of dendrimer - metal nanocomposites as well as functionalized dendrimer - metal nanocomposites. The description of various synthetic methodologies to produce transition metal (Au, Ag, Pd, Pt, and Cu) dendrimer nanocomposites as well as lanthanide ion-cored dendrimers are presented in this review, with further details regarding the basic characterization of these systems. The experimental procedures of the optical measurements used to probe the steady-state and time-resolved dynamics in these novel nanoparticle architectures are provided. Analysis of optical properties of dendrimer nanocomposites (DNCs) includes a description of the characterization of the metal nanoparticles as well as the size and distribution of metal nanoparticles formed by use of organic dendrimer template synthetic procedures ( such as PAMAM). The non-linear transmission properties of certain dendrimer - metal nanocomposites show promising behaviour, which may be useful for applications involving eye and sensor protection. Reports of non-linear transmission properties of both Au and Ag dendrimer nanocomposites are discussed. Metal nanoparticles have also been suggested as useful materials for biological fluorescence imaging and sensing applications. However, it is well known that the efficiency of metal emission is very small. Recent measurements using ultra-fast spectroscopic techniques (fluorescence upconversion) have shed new light on this matter in metal nanoparticles and in dendrimer - metal nanocomposites. Dendrimer - metal nanocomposites have been used to investigate the dynamics of both metal particle emission and the interaction of metal particles with dipolar chromophores. The measurement and mechanism of ultra-fast transient absorption and emission dynamics in metal topologies including dendrimer nanocomposites are also discussed in the review. Future directions regarding the optical properties of dendrimer nanocomposites in the areas of photonics, biology, and medicine are also discussed in this review.