Formation of Hybrid Hydrogels Consisting of Tripeptide and Different Silver Nanoparticle-Capped Ligands: Modulation of the Mechanical Strength of Gel Phase Materials

Abstract

An N-terminally Boc (tert-butyloxycarbonyl) group-protected synthetic tripeptide (Boc-Phe-Phe-Ala-OH) has been found to form a translucent hydrogel in basic aqueous medium. This hydrogel material has been characterized using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transformed infrared spectroscopy, differential scanning calorimetric, X-ray diffraction (XRD), and rheological studies. FE-SEM and TEM studies have revealed the formation of a nanofibrillar network structure upon gelation. Thiol (-SH) containing ligands (amino acid/peptide) have been used to stabilize small silver nanoparticles (AgNPs), and these thiol-capped silver nanoparticles have been incorporated into this hydrogel to prepare hybrid hydrogels. Morphological study of silver nanoparticles containing a hybrid hydrogel (using TEM experiments) has indicated the nice fabrication of AgNPs along the gel nanofibers. Fabrication of nanoparticles upon the gel nanofibers is due to noncovalent interactions between the capping ligands of the nanoparticles and the peptide-based hydrogel nanofibers. Rheological investigations of these hybrid hydrogels have shown the weakening of the mechanical strength of the hydrogel after incorporation of AgNPs within the native hydrogel system. Our studies have vividly shown the dependence of the elastic modulus (G') and yield stress (σ(y)) on three factors: (a) the nature of the stabilizing ligands used for AgNPs, (b) the size of the AgNPs, and (c) the amount of AgNPs used for the preparation of hybrid hydrogel systems. Modulation of the mechanical strength of the hybrid hydrogel can be successfully achieved by varying these above-mentioned factors. This modulation of the mechanical properties keeps a future promise to make tunable soft materials with interesting properties.

Peptide‐Based Hydrogels as a Scaffold for In Situ Synthesis of Metal Nanoparticles: Catalytic Activity of the Nanohybrid System

“…So, the mechanical stiffness of the hydrogel is clearly decreased after the formation of silver nanoparticles within the gel network. There are previous reports that also favors this type of observation ,…”

Triphenylamine‐Based Fluorescent Soft Matter: Interlaced Methyl Cinnamate Groups as the Dominant Interaction Tools for Gel Formation

“…The high aspect ratios of the gel fi bers clearly indicate that the intermolecular interactions between the gelator molecules are highly anisotropic. [ 11 ] As mentioned above, decoration of TPA with acrylates changes their emission behaviors from quenching to emission in the aggregated state. In our research process, it is noteworthy that when the gel with the lowest CGC value (0.62 wt%) in ethanol is warmed from 25 °C to 65 °C, the real-time fl uorescence analysis displays the obvious fl uorescence quenching during gel-sol transformation, and its fl uorescence quantum yield ( Φ F ) value is decreased from 33% to 3.8% (Figure 2 a-c).…”

Multimodal Light-Harvesting Soft Hybrid Materials: Assisted Energy Transfer upon Thermally Reversible Gelation

“…17,18 Some studies have been also devoted to hybrid systems of noble (Ag and Au) metallic nanoparticles NPs and supramolecular networks. 19 In this case, supramolecular gels act as scaffold to support the NPs [20][21][22] which in some of cases were prepared in situ, [23][24][25][26] and can find application as antibacterial soft materials [26][27][28][29] or catalysts. 30 Some studies have evaluated the influence of the molecular gel network in the photoluminescence of NPs.…”