Protein-Mediated Biotemplating on the Nanoscale

Purified proteins offer a homogeneous population of biological nanoparticles, equipped in many cases with specific binding sites enabling the directed self-assembly of envisaged one-, two- or three-dimensional arrays. These arrays may serve as nanoscale biotemplates for the preparation of novel functional composite materials, which exhibit potential applications, especially in the fields of nanoelectronics and optical devices. This review provides an overview of the field of protein-mediated biotemplating, focussing on achievements made throughout the past decade. It is comprised of seven sections designed according to the size and configuration of the protein-made biotemplate. Each section describes the design and size of the biotemplate, the resulting hybrid structures, the fabrication methodology, the analytical tools employed for the structural analysis of the hybrids obtained, and, finally, their claimed/intended applications and a feasibility demonstration (whenever available). In conclusion, a short assessment of the overall status of the achievements already made vs. the future challenges of this field is provided

Novel Biologically Active Silver-Avidin Hybrids

Coupling of biologically active proteins, for example, enzymes and binding proteins, with metals carries huge potential inherent in the integration of these hybrids with miniaturized electronics, medical devices, and in vivo imaging. Here we propose and demonstrate feasibility of the preparation of novel, biologically active silver-avidin hybrids by electroless silver deposition directed to the surface of single, soluble avidin molecules, with retention of their solubility and highly specific biotin binding capacity. The process is based on conjugation of silver ions reducing polymers to avidin surface, followed by the addition of silver ions under mild physiological conditions. The partially overlapping silver patches thus obtained on the protein’s surface provided soluble, biologically active hybrids, retaining their specific biotin binding capability of both low-molecular-weight and high-molecular-weight biotinylated molecules and exhibiting enhanced thermal stability. The hybrids thus obtained were successfully used for molecular imaging of cancer cells prelabeled with biotinylated monoclonal antibody