Recombinant DNA technology has emerged as a useful method for providing protein-based building blocks for nanomaterial assembly. This article provides an overview of the technical aspects of recombinant protein synthesis, especially for nanomaterial scientists and engineers. First, the rationale for the use of protein-based nanomaterials synthesized through recombinant DNA technology is presented. This article then focuses on simple standard protocols for protein expression in Escherichia coli. The last section presents several methods for creating artificial proteins with complex structures.
Fluorescent nanodiamonds (FNDs) have recently attracted much attention as photostable fluorescent probes and sensors capable of quantifying physical parameters in the nanometer region. In this paper, we review the optical properties of FNDs, the surface coating techniques with hyperbranched polyglycerol and polydopamine, and our recent achievements on single particle fluorescence imaging and intracellular thermal conductivity measurements achieved by using the surface-coated FNDs.
Atomic clusters composed of a few or a few dozen atoms are known as a new class of materials exhibiting extraordinary properties. However, design of their structures and properties has been difficult because they have many structural factors in contrast to conventional bulk or nanomaterials. Recently, we have developed a new theoretical model “symmetry-adapted orbital model” for estimating electronic states of clusters. This model was constructed by combining group theory and jellium model in which clusters are approximated by a spherical potential field, and enabled a more accurate prediction of their structures and electronic states. In this paper, we described a theoretical treatment of clusters based on the symmetry-adapted orbital model and its applications.
Fluorescent silica nanoparticles are promising for fluorescent microscopic imaging, including in vitro, in vivo, and multimodal imaging due to their high fluorescence intensity, photostability, multi-functionalization and biocompatibility. The conventional strategy of the preparation of fluorescent silica nanoparticles was mixed with silica source and fluorescent organic or inorganic materials. This study focused on the Au(I)−thiolate complexes, which exhibit photoluminescence with good photostability and large Stokes shifts. We successfully synthesized thiol-organosilica nanoparticles with embedded Au(I)–thiolate complexes (thiol-OS/Au) with red photoluminescence properties. The size-tunable thiol-OS/Au are well biocompatible, good photo- and pH-stable.