Hazardous volatile organic compounds (VOCs) in environmental air have both acute and chronic effects on human health. Gas chromatography coupled with a mass spectrometer (GC- MS) is the most common technology used for analysis of airborne VOCs. However, GC-MS is not effective for on-site measurement of trace VOCs at Superfund sites. The overall goal of this environmental science research project is to develop novel technologies for quantitative analysis of trace VOCs in both the lab and for on-site measurement of toxic, airborne VOCs. We will focus on measurements of acrolein, vinyl chloride, benzene and 1,3-butadiene. The approach is to investigate chemoselective microreactors for capture of Superfund VOCs. Microreactors provide superior advantages of miniaturized device size, very low cost, and fast detection over current sorbent-based tube preconcentrators. We also will develop thiol-modified gold nanoparticle gas sensor arrays for on-site detection of these VOCs. Functionalized thiols will be synthesized to detect target VOCs at a concentration range from sub-ppb to a few ppm. The thiols proposed for modification of gold nanoparticles will have functional groups and structural motifs to specifically promote interaction with and recognition of target VOCs, thus significantly increasing sensing selectivity and sensitivity. The sensors will work at ambient temperature. This research project will lead to transformational technologies for quantitative analysis of trace VOCs. The research is directly related to the overall goals of the Center for investigating the effects of exposure to VOCs on inducing/exacerbating cardiometabolic disease. The project will also have significant broader impacts on monitoring environmental air and on promoting homeland security.