Surface enhanced Raman scattering (SERS) allows gold nanoparticles to act as sensors for chemical and biological pollutants in fluid systems due to gold’s favorable optical properties. For gold nanoparticles to be effective in these applications, their assembly into two dimensional (2D) structures is imperative. Nanoparticle self-assembly into 2D structures is commonly performed at fluid interfaces because it is simple and inexpensive. However, previous studies have shown nanoparticle aggregation and material degradation can be problematic. A current method to avoid particle aggregation at fluid surfaces is to arrange nanoparticles into nanosheets using amphiphilic peptoids. Peptoids, synthetic protein-like polymers, self-assemble into two-dimensional sheet-like structures at fluid interfaces. Previous studies have shown that peptoids guide gold nanoparticles at air-water and liquid-liquid interfaces, packing them into 2D nanosheets structures. While particle aggregation is mitigated, it is still difficult to control the uniformity of gold within nanosheets using solely peptoids, which may affect the sensing ability of gold nanoparticle embedded nanosheets for SERS. The focus of this study is to use a Langmuir-Blodgett trough to assist in the self-assembly and deposition of gold nanoparticle-embedded peptoid nanosheets. Changing controllable parameters on the Langmuir trough such as surface area, nanoparticle size, and solvent, shows promising results for increasing nanoparticle uniformity within the sheets. Photocrosslinking using short wave UV was also incorporated into nanosheet formation, as previous studies suggest that bilayer crosslinking may enhance overall durability and rigidity of nanosheets. This work explored how to enhance peptoid self-assembly into uniform 2D gold nanoparticle embedded structures both with and without photocrosslinking to increase their sensing ability of pollutants in fluid systems.
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