Atomic copper(I)-carbon nitride as a peroxidase-mimic catalyst for high selective detection of perfluorooctane sulfonate

Pursuing a selective and stable optical sensor for the reliable detection of perfluorooctane sulfonate (PFOS) is critical to controlling and reducing the risk of exposure to human. Here, we elaborately prepared an atomic copper(I)-carbon nitride (Cu-CN) peroxidase-mimic catalyst and therefore developed a reliable and accessible PFOS detection method. Well-distributed Cu(I) atoms are exclusively anchored within CN nanosized matrix as identified Cu-CN single-site active centers. Benefiting from the high peroxidase-mimic catalytic capability and colloidal stability, Cu-CN exhibits outstanding detection of PFOS selectively in the range of 0.07 to 3 μM coupled with the detection limit of 14.9 nM. The occupation of atomic Cu(I) specific catalytic sites caused by strong PFOS coordination and the fluorophilic interaction between PFOS should be responsible for the damping of TMB oxidation. Moreover, this detection platform was also used successfully to detect PFOS in three real water samples with RSD ≤ 8.37%. This well-established colorimetric sensing system based on peroxidase-mimic capability of single-atom catalyst is promising for the detection of other hazards in aquatic environment.