LAUSR

Mercury ion (Hg2+), a bioaccumulating and toxic heavy metal, can cause severe damages to the environment and human health. Therefore, development of high-performance Hg2+ sensors is highly desirable. Herein, we construct a uniform dodecahedral shaped N-doped carbon decorated by single Fe sites enzyme (Fe-N-C SAE), which exhibits a good performance for Hg2+ detection. The N atom on Fe-N-C SAE can specifically recognize Hg2+ through the chelation between Hg2+ and N atom, while the catalytic site on the single-atom enzyme acts as a signal amplifier. The Fe-N-C SAE functionalized solution-gated graphene transistor exhibits a dramatic improvement in the selectivity and sensitivity of the devices. The sensor can rapidly detect Hg2+ down to 1 nM within 2 seconds. Besides, a relatively good repeatability and reproducibility for the detection of Hg2+ has also been found in our sensor platform. Our findings expand the application of single atom catalyst in the field of food safety and environmental monitoring.