Fabrication of ZnSe Nanoparticles in the Apoferritin Cavity by Designing a Slow Chemical Reaction System

Abstract

Zinc selenide nanoparticles (ZnSe NPs) were synthesized in the cavity of the cage-shaped protein apoferritin by designing a slow chemical reaction system, which employs tetraaminezinc ion and selenourea. The chemical synthesis of ZnSe NPs was realized in a spatially selective manner from an aqueous solution, and ZnSe cores were formed in almost all apoferritin cavities with little bulk precipitation. Three factors are found to be important for ZnSe NP synthesis in the apoferritin cavity: (1) the threefold channel, which selectively introduces zinc ion into the apoferritin cavity, (2) the apoferritin internal potential, which favors zinc ion accumulation in the cavity, and (3) the nucleation site, which nucleates ZnSe inside the cavity. The characterization of the synthesized ZnSe NPs by X-ray powder diffraction and energy-dispersive spectrometry revealed that the synthesized NPs are a collection of cubic ZnSe polycrystals. It was shown that the 500 degrees C heat treatment for 1 h under nitrogen gas transformed the polycrystalline ZnSe core into a single crystal, and single-crystal ZnSe NPs free of protein were obtained.

Floating nanodot gate memory fabrication with biomineralized nanodot as charge storage node

“…Efforts for the artificial biochemical synthesis enabled the nanoparticle formation of various materials in a hollow cavity in vitro, such as transition metal ͑Fe, Co, Ni͒ oxides and semiconductor nanodots. [16][17][18] Artificially biomineralized nanodots are uniform in size and shape due to the restricted inner cavity size and shape of protein shell. Chemical flexibility of protein outer surface made the formation of high-density two dimensional inorganic nanodot arrays 19 and selective deposition 20,21 possible, and vulnerability of protein made the selective removal of organic residues possible.…”

Biological path for functional nanostructure fabrication and nanodevices

“…It was proved that zinc ions accumulated at the negative glutamic acid residues on the cavity Biological path for functional nanostructure fabrication and nanodevices Yamashita surface and where zinc selenide nuclei was formed. 15 The author also applied the SCRY, replacing selenourea with thiourea and successfully producing cadmium sulfide, zinc sulfide (ZnS), copper (II) sulfide (CuS), silver sulfide (AgS) and gold (I) sulfide (Au 2 S) NPs (Figure 3). …”

Apoferritin: protein nanocarrier for targeted delivery

“…These channels are 1.2 nm long and 0.3-0.4 nm wide [44] and they are formed by contact between the H5 helices of four subunits from this axis, oriented from the outer to the inner part of the protein shell [18]. In contrast, eight three-fold channels are hydrophilic, 0.3-0.4 nm long and wide [44] and consist of negatively charged glutamic and aspartic acid residues [53,54]. They are formed by a symmetrical convergence of three subunits at this axis which are in contact through the N-terminal ends of helices H1 and H4 and the C-terminal ends of H2 and H3 [55].…”

“…These properties can be achieved not only by using the nanoreactor route but also by using apoferritin shell reassembly in the presence of target NPs [63]. [53,65,[70][71][72][73]. The scheme of NP synthesis using apoferritin is presented in Figure 3.…”