▎ 摘　　要

A chemiresistor sensor for ultra-low levels of elemental mercury (Hg-0) vapor is described. The sensor was prepared through thermal reduction of graphene oxide (GO) deposited on an interdigitated electrode using only low temperature annealing typically at 230 degrees C. The sensor responds to the presence of Hg-0 vapor within <1 min and spontaneously recovers its baseline through flushing with a Hg-0-free carrier gas. The sensor has a linear response in the range of 0.5 to 12.2 ppb(v) of Hg-0 vapor and a detection limit of 0.10 ppb(v). The amount of GO and annealing temperature affect the sensor response and were optimized. The sensor can find use in monitoring exposure of persons to Hg-0 vapors, for which a threshold value of 6.1 ppb(v) has been set by the World Health Organization.