UC Riverside

In light of growing concern over environmental, safety, and health issues, our modern world exhibits a strong demand for devices capable of quickly measuring analytes of interest. To meet that goal, recent innovation has been driven by exploiting the benefits of nanotechnology to create advanced sensing devices. While many nanofabrication techniques require a clean room and expensive instrumentation, electrospinning has emerged as a low-cost method of fabricating devices for the detection of biologically significant targets. This dissertation is a comprehensive account of research efforts aimed at developing novel detection platforms using electrospun materials functionalized with conjugated polymers, electrically conductive polymers, carbonaceous materials, and metal noble nanoparticles. To that end, this work explores methods of improving sensing applications of electrospun nanofibers for various volatile organic compounds (VOCs) using optical and electrochemical techniques.

The first section of this work explores a colorimetric approach to the detection of organic amines using a nanofibers-based sensor array doped with a class of conjugated polymers known as polydiacetylenes (PDAs). This sensor demonstrates innovation over previous studies found in the literature via detection of sub-saturation concentrations of VOCs, and by applying machine learning to colorimetric patterns to distinguish different amines based on unique interactions with the different components of the sensor array. In the second section of this work, a polyaniline (PANi)-based nanofiber chemiresistor sensor is doped with different graphene oxide variants for the detection and classification of small alcohol vapors—a partially-reduced graphene oxide dopant was shown to greatly improve the performance of the sensor. In the third section, the synergistic effect of metal-enhanced fluorescence (MEF) between silver nanoparticles and PDA is explored both in silico and experimentally in two different realms: bulk nanofiber mats and within single nanofibers.