Development of Highly Sensitive Portable Hydrocarbon Sensors

摘要

A detailed investigation was performed on developing highly sensitive and portable hydrocarbon sensors using tailored quantum dot materials. These studies focused on using an Ocean Optics fiber optics based spectrometer for monitoring quantum dot arrays to detect the hydrocarbon targets. Studies were performed to determine the viability of using arrays for these studies, tailoring the quantum dot materials for higher sensitvity through energy transfer mechanisms, and tailoring the materials for enhanced stability. These studies showed that monitoring quantum dot arrays using a portable spectrometer, while aviable method, requires the reliable synthesis and subsequent reliable stability of the quantum dots. While CdSe quantum dots with tailored surface ligands were shown to be able to detect hydrocarbons with a 15ppm detection limit, the repeated synthesis and stability studies determined that these quantum dots suffer from reliability issues on both counts, which inhibited their use in long term development studies. In the absence of stable quantum dots, a study was performed which utilized ZnS capped CdSe quantum dots. These studies have proven that even without surface tailored ligands, hydrocarbons were detected with in a 15-9400 ppm detection range, and more so they showed stability over an 8 month time period. These were significant improvements obtained in these studies.