Deposition of Zinc Oxide and Layered Basic Zinc Salts from Aqueous Solutions Containing Amino Acids and Dipeptides

Abstract

Deposition experiments from aqueous solutions of zinc nitrate were performed in a bio-inspired way using biomolecules as directing agents. A global overview of the effect of various amino acids 8 and dipeptides 21 was done in term of structure and morphology of the obtained coating. The selection of certain biomolecules leads to the formation of smooth ZnO thin films. Variations of the amino acid chemical function and the sequence used within the peptides combination give rise to a wide variety of morphologies ranging from films to three dimensional nets. The data obtained from scanning electron microscopy and X-ray diffraction are discussed and correlated to the chemical properties of the biomolecules.

Direct evidence of ZnO morphology modification via the selective adsorption of ZnO-binding peptides

“…The most commonly used approach is that involving SDAs ranging from simple molecules, such as amines [13][14][15][16] and anionic species, [17][18][19][20][21] to polymers (DBCP, [22][23][24][25][26][27][28][29] PVP, [30][31][32][33][34][35][36][37][38][39][40][41][42] PAM, 29 and PAH 43 ) and biomolecules. [44][45][46][47][48][49][50][51][52] The SDAs have been shown to affect the morphology of ZnO by imposition of effects on nucleation and/or growth of the crystals. Among these SDAs, biomolecules have received little attention in ZnO synthesis because of their complexity, high cost, and sensitivity to reaction conditions.…”

“…53,54 Secondly, some biomoleculedirected syntheses have been shown to impose exquisite control on ZnO morphology/structure; [44][45][46]48,50,51,55 improve ZnO crystallinity; 50 template ZnO formation; 47,49,52,56 catalyze ZnO formation; 57,58 and also suppress ZnO formation. 44,45 These diverse effects can possibly be used to tune the morphology/ structure-related properties of ZnO and thus its applications. Thirdly, biomolecules show remarkable recognition capabilities, functional specificity and multi-functional characteristics which may contribute to high efficiency and accuracy in ZnO structure tailoring.…”

“…As an example, ZnO films have been formed on substrates in the presence of histidine and/or its dipeptides, however, when these biomolecules were absent, discrete ZnO microcrystals were obtained. 44,45 In another study, the change of reactant concentrations, including variation of histidine concentration, generated ZnO particles with diverse morphologies including microrods, flowers, and microshells. 48 ZnO microshells can also be produced by the use of cysteine 59 while the use of a urease enzyme has been shown to produce nanoshells with potentially tunable diameters.…”

“…Hitherto, evidence for the ability of biomolecules to tune ZnO morphology has been gained for single amino acids, 44,45,48,59 short peptides, 44,45,46,58 through to complex macromolecules such as proteins. 47,50,51,57,72,74 However, the focus of research in this area has been generally application-driven, and a mechanistic understanding of biomolecule-mediated ZnO formation remains incomplete.…”

Template-controlled mineralization: Determining film granularity and structure by surface functionality patterns

“…These NPs grow in solution under the presence of histidine. Gerstel et al [26,27] found that histidine controls NP growth and is incorporated in the resulting films. XRD measurements show that the deposited ZnO is X-rayamorphous (data not shown).…”