Porous 2D FeS2 nanosheets as a peroxidase mimic for rapid determination of H2O2

Considering the threat of H2O2 to human health and environmental security, it is of great significance to develop rapid, accurate and sensitive analytical methods for H2O2 detection. In this work, porous regular hexagonalshaped FeS2 nanosheets (NSs) with a side length of about 1 mu m are employed as a peroxidase mimic to detect H2O2. The Km of the FeS2 NSs for H2O2 (0.00342 mM) is much lower than actual enzyme HRP (3.7 mM). The FeS2 NSs exhibit high sensitivity in linear range of 0.02-4.00 mu M of H2O2 with a limit of detection (LOD) of 7.60 nM (S/N = 3). The Fe ion in the FeS2 NSs is the active site. No obvious effect on the determination was found when K+, NH4+, Ni2+, Mn2+, Cu2+, Zn2+, Al3+, Ba2+, Ca2+, NO3-, glucose and sucrose were added in the solution, respectively. The FeS2 NSs were also applied to rapidly detect H2O2 concentrations in different actual samples, such as lens solution, beer and disinfectant.