Gold nanoparticles have favorable optical properties that are utilized in sensing chemical and biological pollutants in fluid systems using surface enhanced Raman scattering (SERS). Two dimensional arrangements of metallic nanoparticles enhance SERS signals by creating sensing “hot spots” and large areas for sequestering pollutants. One current method to arrange nanoparticles into two dimensional (2D) structures utilitzes amphiphilic peptoids. Peptoids, synthetic protein polymers, self-assemble into two dimensional sheet-like structures at fluid interfaces. Previous studies have shown that peptoids may be used to guide gold nanoparticles at the air-water interface, packing them within the nanosheets to adopt a 2D structure. However, it is difficult to control the uniformity of gold within nanosheets using this method, which may affect the sensing ability of these gold nanoparticle embedded nanosheets. This work explores how to enhance peptoid self-assembly into uniform two dimensional gold nanoparticle structures. A Langmuir-Blodgett trough is used to assist in the self-assembly and deposition of nanosheets. Optical microscopy has shown that gold clumping and nanosheet degradation frequently occur at the air-water interface with unoptimized conditions. Changing controllable parameters on the Langmuir trough such as surface area, and nanoparticle size and solvent, shows promising results for increasing uniformity among sheets. The significance of this study is to increase the overall uniformity among sheets to increase their sensing ability of pollutants in fluid systems.

Synthesis of uniform gold nanoparticle embedded peptoid nanosheets

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.