Chemoenzymaticly Prepared Oligopeptides for Synthesis of Silica Colloidal Particles and Metal Nanoparticles/Mesoporous Silicas and Their Application as Catalyst

Abstract

In this study we report the facile green synthesis of oligopepeptides silica/peptide colloidal particles mesoporous silicas and metal/silica hybrid materials Chemoenzymatic synthesis of peptides is a clean chemistry technique that allows fast prodution under mild conditions Here we synthesized oligo(L-lysine-co-L-tyrosine) [oligo(KY)] and oligo(L-lysine-co-L-phenylalanine) [oligo(KF)] by bromelain as well as characterizing in terms of yield molecular weight and composition of the oligopeptides The silica/peptide colloidal particles can be simply fabricated by silica mineralization of oligo(KY) and oligo(KF) Tuning the tetraethyl orthosilicate (TEOS) concentration caused the size of the silica/peptide colloidal particles between 150 and 430 nm and isoelectric point (pI) between 3 2 and 4 2 After removing the oligopeptide mesoporous silicas exhibited pore size between 3 and 5 nm by replication of sheet-like peptides In addition the as-prepared silica/peptide colloidal particles served as reducing agents for the nucleation of metal nanoparticles (NPs) Next the Ag/Pd alloys-based silica hybrid materials were obtained through the galvanic replacement reaction After calcination the metal/silica hybrid materials were obtained The experimental data revealed that the metal/silica hybrid materials showed reliable catalytic activity in reducing 4-nitrophenol (4-NP) with a pseudo-?rst-order reaction rate

Date of Award	2019
Original language	English
Supervisor	Jeng-Shiung Jan (Supervisor)