The emphasis of study of small inorganic particles is shifting from th
e single particle to self-assembled aggregates of particles. According
ly, the colligative properties of ensembles have also become a focus o
f interest. Advances in the synthesis and in the understanding of the
physical properties of ensembles have led to the practical utilization
of such networks and arrays, and this trend seems set to continue in
the future. Molecular control over the process of particle self-assemb
ly will allow the tailoring of the production of two- and three-dimens
ional arrays of nanoparticles for a variety of specific applications,
probably in optical microelectronics and sensor technologies.