title: Nanoparticles comprising a mixed monolayer for specific bindings with biomolecules.
abstract: This work presents a strategy of using mixed monolayer protected nanoparticles for specific interactions with target biological molecules. The mixed monolayer is composed of a shielding component and a capture component. The shielding component utilizes ethylene glycol oligomers to prevent nonspecific binding with biomolecules. The capture component is chosen to specifically interact with the target of interest, such as a protein molecule. Such a concept was demonstrated by two synthetic systems. The first one is gold nanoparticles protected by a mixed monolayer of tri(ethylene glycol) thiol (EG(3)-SH) and tiopronin (Tp), which was prepared by a one-step synthesis. Surface chemical composition studies using (1)H NMR spectroscopy revealed that the reactivity of EG(3)-SH is 3 times as high as that of Tp in the nanoparticle formation. Gel electrophoresis analysis identified a critical ratio of (EG(3)-S-)/Tp on the nanoparticle surface above which no nonspecific binding occurred. By further derivatizing Tp into a biotin group, we synthesized Au(-S-EG(3))(n)/Tp-biotin particles that bind specifically to streptavidin with negligible nonspecific binding. The second system is gold nanoparticles protected by a mixed monolayer of EG(3)-SH and glutathione (GSH). By controlling the feeding ratio of EG(3)-SH and GSH, we made Au(-S-EG(3))(n)/GSH particles that bind specifically to gultathione-S-transferase (GST) with negligible nonspecific binding.
authors.affiliation: Central Research and Development, Du Pont, Experimental Station, Wilmington, Delaware 19880, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Zheng
authors.forename: Xueying
authors.initials: X
authors.lastname: Huang
mesh_terms: D001710:Biotin / Q000737:chemistry; D004586:Electrophoresis / Q000379:methods; D005978:Glutathione / Q000737:chemistry; D005982:Glutathione Transferase / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism; D049329:Nanostructures / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D011506:Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D019809:Streptavidin / Q000737:chemistry; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry; D013499:Surface Properties; D008625:Tiopronin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D011506:Proteins; D013438:Sulfhydryl Compounds; C028914:triethylene glycol; D011092:Polyethylene Glycols; D001710:Biotin; D006046:Gold; D019809:Streptavidin; D008625:Tiopronin; D005982:Glutathione Transferase; D009113:Muramidase; D005978:Glutathione