Presentation Title

Synthesis of Gold Nanorods Using C12EDMAB as a Less Toxic, Alternative Growth-Directing Agent

Location

Nessmith-Lane Atrium

Session Format

Poster Presentation

Research Area Topic:

Natural & Physical Sciences - Chemistry

Abstract

Over the last 15 years the number of publications centered around nanoparticles has increased significantly. A large majority of these papers are devoted to the use of these materials as therapeutics including cancer, bacteria, viruses, and their ability to serve as controlled release drug vehicles. Gold nanoparticles have been the subject of many such investigations owing to their interesting optical properties, long-term stability, and minimal cytotoxicity. Gold nanorods are often synthesized following a seed-mediated protocol in the presence of the cationic surfactant hexadecyltrimethylammonium bromide (CTAB) with great success. This approach involves the use of the growth-directing agent, cetyltrimethylammonium bromide (CTAB) in the presence of gold salt, a weak reducing agent, and silver ions. CTAB forms a micelle bilayer on the side faces of the gold promoting rod-like growth. Though effective, CTAB possesses properties that are hazardous to the environment. Because of their increased uses in biomedical related research, a great deal of effort has been spent masking the CTAB bilayer by over-coating it with non-toxic materials such as charged polyelectrolytes, polymers, and silica. However in at least one case, this was found to be futile when polyelectrolyte PSS was used to mask the CTAB and the resulting PSS/CTAB complex, when leached from the nanorod surface, was found to be more toxic than CTAB alone. In the current study we have investigated the alternate cationic surfactant, dodecylethyldimethylammonium bromide (C12EDMAB), as a possible growth-directing alternative. C12EDMAB has been found to have similar capabilities as those of CTAB with respect to gold nanorod synthesis yet will potentially pose a smaller threat to environmental safety and overall health based on suggested MSDS data. In addition to successful gold nanorod growth as measured by UV-Vis spectroscopy and transmission electron microscopy, evidence of aspect ratio control from added AgNO3 has been found and is consistent with the well-documented CTAB approach. Furthermore, cell studies suggest that at specific concentrations rods coated with C12EDMAB are less toxic in HEp-2 cells over 48 hours as measured by MTT.

Presentation Type and Release Option

Presentation (Open Access)

Start Date

4-16-2016 10:45 AM

End Date

4-16-2016 12:00 PM

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Apr 16th, 10:45 AM Apr 16th, 12:00 PM

Synthesis of Gold Nanorods Using C12EDMAB as a Less Toxic, Alternative Growth-Directing Agent

Nessmith-Lane Atrium

Over the last 15 years the number of publications centered around nanoparticles has increased significantly. A large majority of these papers are devoted to the use of these materials as therapeutics including cancer, bacteria, viruses, and their ability to serve as controlled release drug vehicles. Gold nanoparticles have been the subject of many such investigations owing to their interesting optical properties, long-term stability, and minimal cytotoxicity. Gold nanorods are often synthesized following a seed-mediated protocol in the presence of the cationic surfactant hexadecyltrimethylammonium bromide (CTAB) with great success. This approach involves the use of the growth-directing agent, cetyltrimethylammonium bromide (CTAB) in the presence of gold salt, a weak reducing agent, and silver ions. CTAB forms a micelle bilayer on the side faces of the gold promoting rod-like growth. Though effective, CTAB possesses properties that are hazardous to the environment. Because of their increased uses in biomedical related research, a great deal of effort has been spent masking the CTAB bilayer by over-coating it with non-toxic materials such as charged polyelectrolytes, polymers, and silica. However in at least one case, this was found to be futile when polyelectrolyte PSS was used to mask the CTAB and the resulting PSS/CTAB complex, when leached from the nanorod surface, was found to be more toxic than CTAB alone. In the current study we have investigated the alternate cationic surfactant, dodecylethyldimethylammonium bromide (C12EDMAB), as a possible growth-directing alternative. C12EDMAB has been found to have similar capabilities as those of CTAB with respect to gold nanorod synthesis yet will potentially pose a smaller threat to environmental safety and overall health based on suggested MSDS data. In addition to successful gold nanorod growth as measured by UV-Vis spectroscopy and transmission electron microscopy, evidence of aspect ratio control from added AgNO3 has been found and is consistent with the well-documented CTAB approach. Furthermore, cell studies suggest that at specific concentrations rods coated with C12EDMAB are less toxic in HEp-2 cells over 48 hours as measured by MTT.