Study On The Modification Of Gold Nanoparticles By Biomolecules

Gold nanoparticles have drawn intense interest in the field of environment. The interaction of biomolecules and nanoparticles still has controversy. This study focused on the interaction mechanism responsible for lysine-gold nanoparticles system, and the establishment of AuNP-lysine oligomers system and AuNP-targeting peptide systems.Firstly, AuNP-aminocaproic acid, AuNP-lysine, AuNP-tetramer lysine (KKKK) were prepared, and then characterized by UV, Laser Particle Size Analyzer, FTIR, RAMAN, NMR. Among them, UV and laser particle size analyzer were used to study the stability of the system, and FTIR, RAMAN were used to identify modification results, and NMR was used to examine the interaction of gold nanoparticles and ligands. The results show that both α-NH2and ε-NH2of lysine were combined with gold nanoparticles at low pH (pH<5), which caused the aggregation of gold nanoparticle colliod, and only α-NH2bound to gold nanoparticles at high pH(5≤pH≤10). For AuNP-aminocaproic acid system, the aminocaproic acid bound to gold nanoparticles by the ε-NH3at low pH (pH<5) and counld not bind to gold nanoparticle at other pH.Secondly, the kinetics scanning of AuNP-KK, AuNP-KG showed that the ε-NH2of lysine monomer did not combined with the gold nanoparticle, while the ε-NH2of Lysine oligomers could conjugate the gold nanoparticle.Moreover, for building functional AuNP-peptide system, the pH, AuNP volume/peptide volume and stirring speed were optimized. Under optimal conditions, AuNP-IF7AuNP-IF7C, AuNP-IF7DDDD, AuNP-IF7CDDDD, AuNP-DDDIF7and AuNP-DDDIF7C stable dispersion system were prepared, which were characterized by SEM, TOF and FTIR.