Project Abstract Our proposed project, “Plasmonic mercury sensor and wearable gas detector,” will develop a miniaturized and low-cost mercury sensor and apply it to personal exposure monitoring. This project will demonstrate the feasibility of a powerful and sensitive mercury vapor sensor that is less than 0.2 cm3 in volume, draws less than 1 Watt, and costs less than $40 in parts. During this project our sensor will be integrated into a personal monitor to be the first personal mercury monitor that is wearable, immediate, and accurate in complex environments. Newly available integrated optical modules will be employed to measure the plasmonic signal of an amalgam nanoparticle film. Picoyune’s proprietary plasmonic mercury sensing technique is uniquely capable of measurements in complex mixtures. The development of such a unique device will benefit all parties concerned with mercury exposure. These include artisanal and small-scale gold mining communities, other mining, dental offices, hospitals, laboratories, schools, and industrial sites. Mercury monitoring costs hundreds of millions of dollars a year across diverse scientific, industrial, and regulatory groups.