Abstract

Nanotechnology is applicable to many different fields including electronics, drug delivery, structural materials, and sensors. The research presented here explores the development of a nanoparticle-based sensor that will detect small organic compounds such as fungicides, herbicides, and pesticides. The main components of these sensors are silicon dioxide nanoparticles due to their ability to self-assemble into nanoporous crystals, thus effectively creating a filtration system. The device’s sensing surface consists of gold nanoparticles, which is chosen due to favorable optical properties and the ease of surface modification. In order to create a uniform colloidal crystal with consistent pores, the nanoparticles must be similar in size. Nanoparticle syntheses, however, are very sensitive to reaction conditions, making it difficult to consistently synthesize size-matched particles. We explore different variables such as reactant concentrations, mixing conditions, and temperature to control and achieve size matching between silicon dioxide and gold nanoparticles.