Short peptide mediated self-assembly of platinum nanocrystals with selective spreading property

Abstract

Spherical assemblies with core/shell configurations are prepared through C-terminal amidated short peptide mediated self-association of platinum nanocrystals. The interactions between the peptides might drive the self-assembly of platinum nanocrystals and determine their surface properties. Thus, the nanosize assemblies collapse and spread on a hydrophilic surface, whereas maintaining their spherical shapes on a hydrophobic surface.Noble metal nanocrystals (NMNCs) possess fascinating properties, including catalytic, optical and electrical performance, and have been considered as superior building blocks for multifunctional materials. 1-4 It has been well known that many properties of the materials are dependent not only on the size, shape and composition of the building blocks, but also on their spatial conformations in the superarchitecture. 1-6 Recently, signicant progress has been made in assembling NMNCs into sophisticated superarchitectures, for example, threedimensional (3D) superspheres. 7-10 These superarchitectures have shown potential for fascinating applications in drug delivery, 11 bioimaging, 12 and catalysis. 9,13,14 In previous studies, sulfur-containing chemicals, e.g. thiols and thioethers, were mainly used as the cross-linking agents, and the assembly methodology involved organic solvents and complicated approaches, such as place-exchanging and exchanging-crosslinking. [15][16][17][18] In contrast, the self-assembly of NMNCs into well-dened functional superstructures through an easy, efficient and environment-friendly approach is still less reported, and the quest is continuously ongoing. 19 Herein, we present a type of 3D core/shell nanoassembly, easily formed by platinum nanocrystals (Pt NCs) using a short peptide as the cross-linking agent in an aqueous solution and demonstrate their selective wetting and spreading properties on a hydrophilic substrate, as shown in Scheme 1.Previously, a hepta-peptide with the sequence of NH 2 -TLHVSSY-COOH, named P7A, was found to stabilize ultra-small Pt NCs with a diameter of 1.7-3.5 nm in an aqueous solution by specically binding to their surfaces. 20-26 Our recent study revealed that the C-terminal carboxyl group of P7A is crucially important for stable dispersion of the Pt NCs in an aqueous solution, providing pH-dependent electrostatic repulsive intereactions. 27 Therefore, it will be interesting to screen such electrostatic repulsions through amidation of the carboxyl group. With an FMOC solid phase peptide synthesis (SPPS) strategy, we Scheme 1 Schematic of P7A-NH 2 mediated Pt NCs assembly into core/shell nanoassemblies with the ability of selectively wetting and spreading on the hydrophilic surface.

Short Ligand, Cysteine-Modified Warnericin RK Antimicrobial Peptides Favor Highly Sensitive Detection of Legionella pneumophila

“…XPS data for bare and peptide functionalized (50 μg/mL) GaAs surfaces are presented in Figure b,c. The C 1s spectra for both functionalized and non-functionalized samples were observed at 284.8 eV, ascribed to C–H and C–C bonds . The peak at 286.3 eV could be assigned to the carbon atoms of the CO or C–N , or to the OCN. , The amide related peak at 288.08 eV, , observed only for the functionalized sample, confirms the presence of peptides.…”

Inkjet Printed Nanopatterned Aptamer‐Based Sensors for Improved Optical Detection of Foodborne Pathogens

“…The N1s peak was decomposed in four subpeaks at 398.9, 399.6, 399.9, and 401.3 eV (Figure e), corresponding to the amine‐rich PEI layer deposition as described by Louette, and amide groups. The peptide bond formed after carboxyl/ssDNA immobilization was confirmed by the amide and carbonyl peaks (Figure f) at 401.34 and 530.5 eV respectively which is in line with the typical energies of assembled peptides . The elemental molar ratios experimentally obtained support the conclusion that more than 63% of the total N corresponds to the ss‐DNA aptamer which is in total agreement with the theoretical molar ratios calculated ( Table 1 ).…”

Controlling the Self-Assembly of Biomolecules into Functional Nanomaterials through Internal Interactions and External Stimulations: A Review

“…Biomolecules can also be conjugated with other nanomaterials, such as graphene or NPs, to form functional nanomaterials via a hydrophobic interaction [ 67 , 68 , 69 , 70 ]. For example, Lu and co-workers developed a novel fluorescent approach to monitor peptide–protein interactions based on the assembly of a pyrene-labeled peptide on GO via both π–π and hydrophobic interactions [ 71 ].…”