Book excerpt: Increasingly, novel optical and magnetic properties of nanoparticles and nanowires are finding rich opportunities in electronic, biological tagging, separation and sensing. This volume brings together a large and diverse group of international researchers to focus on the synthesis, processing, characterization and modeling of nanoparticles and nanowires and their potential use as 'nanoscale building blocks' for electronic, optical and biological applications. The compilation of papers reflects the drive to harness the understanding of isolated nanostructures, translating these insights into opportunities of engineered materials and devices. In addition to studies of individual nanostructures, the volume also explores how new collective properties emerge as nanoscale building blocks are assembled to produce extended structures. Experimental, theoretical and computational perspectives are offered. Topics include: magnetic nanostructures; metallic nanoparticles; metallic nanowires; magnetic and metallic nanostructures; semiconductor quantum dots; semiconductor dots and wires; nanobiological materials; and group-IV nanoparticles.