Bioassisted Room‐Temperature Immobilization and Mineralization of Zinc Oxide—The Structural Ordering of ZnO Nanoparticles into a Flower‐Type Morphology

Abstract

tate and methyl benzoate (90:10 w/w) and used for the thickness-period library. Different amounts of this mixture were dispensed using a micropipette (Brand Transferpette) in the different columns. Solvent was evaporated under ambient conditions. Thicknesses were characterized using a stylus profilometer (Dektak 3M). The same mixture of solvents was used for the composition-period libraries.The exposure was performed using an USHIO lithographic system (filter at 365 nm, intensity 5 mW cm -2 ). After exposure and heating, all the samples were fully polymerized by flood exposure for 10 min and heating at 80°C for an additional 10 min to fix the relief structure. We checked that this step had a minor influence on the final relief structure. The topography was measured using an automated atomic force microscope (NT-MDT Solver P7 LS, Moscow, Russia) with a motorized Yh-stage. The stage moves automatically to the 44 programmed coordinates on the sample surface corresponding to different processing conditions (e.g., energy-period, temperature-period). In case of the temperature-period library, the sample was virtually divided into 44 samples (11 × 4) and temperatures were estimated using a contact thermometer. All samples were prepared in a clean room (class 100). Recent advances in biotechnology enable us to identify peptides with an affinity for non-biological materials and, in particular, those that mediate the mineralization of inorganic matter. The use of functional peptides is attracting immense interest in the development of bottom-up fabrication procedures of nanometer-scale devices. In biological systems, proteins such as silicatein, [1] silaffins, [2,3] and ferritin [4,5] cause the deposition of inorganic matter inside or around the cell where the nucleation and growth of these materials is controlled. These proteins are being utilized in vitro for the creation of nanostructured materials. [6][7][8] Recently, artificial peptides with an affinity for non-biological inorganic materials have been discovered by means of a combinatorial library approach, [9,10] and these peptides are known to have the potential for mineralization. For example, peptides with an affinity for metals and semiconductors, such as gold, silver, silica, zinc sulfide, and cadmium selenide, can be used to synthesize crystalline nano-to micrometer-sized metal particles.

Genetically Modified Collagen‐like Triple Helix Peptide as Biomimetic Template THIS CHAPTER HAS BEEN RETRACTED

“…Crystalline ZnO could not be grown on the triple helix at high pH without ZnO-1 peptide, and it indicates that the ZnO-1 peptide catalyzes the growth of single crystalline ZnO under these extreme conditions. Previously, Umetsu et al 72 reported that cysteine in the GGGSC tag of the ZnO-1 peptide was required to grow flower-like ZnO microparticles at room temperature, and the combination of this GGGSC tail and the rest of the amino acid residues, EAHVMHKVAPRP, is likely to be important in the growth of single crystalline ZnO nanowires at low temperature and pH 10.0; at pH 10.0, cysteine is negatively charged and this negative charge recruits positive zinc ions onto the template nanowires efficiently. Then, the basic amino-acid-dominant EAHVMHKVAPRP part could produce local pH and charge distributions at the molecular level that favor the condensation of the intermediates and catalyze the dehydration to produce ZnO.…”

“…4,69 Using the same strategy as in the case of the Au coating, a synthetic peptide, ZnO-1 (Glu-Ala-His-Val-Met-His-Lys-Val-Ala-Pro-Arg-Pro-Gly-Gly-Gly-Ser-Cys), which has a high affinity for ZnO crystals and catalyzes ZnO growth at low temperature, was attached to the F877 template via hydrogen bonding. 69,72 This ZnO-1 peptide-coated F877 triple helix was used for the ZnO nanowire growth. When zinc acetate was hydrolyzed on the ZnO-1 peptide-coated triple helix at pH 10.0 at 4 C for 9 days, ZnO nanowires were obtained from the supernatant of the growth solution via centrifugation, as shown in Figure 9.9a.…”

“…ZnO has a wide bandgap (3.37 eV) and possesses unique optical, acoustic, catalytic, and electronic properties, which makes ZnO one of the most widely studied semiconductors in the application of solar cells, sensors, ultraviolet nanolasers, catalyst, transparent conductor, piezoelectric materials, and short-wavelength light-emitting devices. [70][71][72][73] It requires the fabrication of morphologically and functionally distinct ZnO nanostructures. While recently various methods have been published to grow ZnO in various shapes at near room temperature, there have been no reports on controlling the size and monodispersity of ZnO nanowires at temperatures lower than room temperature.…”

Nanoparticle Synthesis in Vesicle Microreactors

“…Even though the widespread speculations propose that a few enzymes or peptides present in the organic matrix (mainly in cell walls and periplasmic space) act as reducing and nucleation sites (Mukherjee et al, 2001;Ahmad et al, 2002;Dameron et al, 1989;Umetsu et al, 2005;Kröger et al, 2006;Naik et al, 2002), the molecular basis for the biosynthesis of these materials is not well established. Currently, there are two main directions of research in this field.…”

Identification of peptide motif that binds to the surface of zirconia

“…The tactic of this method is to isolate the peptides that bind specifically to a target from a random peptide library, which displays peptides of 10 9~1 0 10 variants on the tip of the minor protein pIII of a filamentous phage named M13 16,17) . A simple method allowing the creation of peptides without immunization of animals, the phage display method has recently been utilized not only for organic materials [18][19][20][21][22] , but also for several inorganic materials 12,[23][24][25][26][27][28][29] . However, a peptide that binds to zirconia has yet to be identified.…”