ABSTRACT
Growing interest in research on nanoparticles is to a great extent motivated by their numerous applications in ™elds of life science, chemistry, technology, as well as materials and environmental research [1-5]. Focus of attention are custom-made nanoparticles, since their properties can be engineered according to the needs of applications. Powerful synthesis approaches of such nanoparticles reach from plasmas and Ÿames [6,7] to colloidal chemistry [8-10]. This requires a variety of analysis techniques, which are commonly used to determine the particle size and size distribution, as well as to optimize synthesis conditions. This includes electron microscopy, such as transmission and scanning electron microscopy (TEM, SEM), where the dry nanoparticles are studied [11]. Alternatively, scanning probe microscopy (SPM) has been used [12]. Static and dynamic light scattering (DLS) are standard techniques for probing the size of nanoparticles in solution [13], where swelling, aggregation as well as bulky ligand shells can explain different sizes and size distributions compared to studies using electron microscopy [14]. In addition, the advanced analysis of properties of nanoparticles requires spectroscopic approaches, which permit to determine not only their size and size distribution, but also their surface and bulk properties. Conventional approaches include infrared, visible, ultraviolet, and Raman spectroscopy [15-17]. Further studies made use of soft x-rays, where the electronic structure [17-21] and small angle scattering [22] were probed. Spectroscopic work on nanoparticles has been combined with optical microscopy approaches [23] or more advanced techniques, such as near-™eld microscopy [24], stimulated emission-depletion (STED)-microscopy [25], tunnel-and force microscopy [12], as well as tip-enhanced approaches
16.1 Introduction .......................................................................................................................... 401 16.2 Experimental ........................................................................................................................402 16.3 Results and Discussion .........................................................................................................403
