High peroxidase catalytic activity of exfoliated few-layer graphene

Few-layer graphene prepared from graphite exfoliated by chitosan has a preserved structure without oxidation or destruction of the sp2 character of the carbon plane and exhibits a higher peroxidase catalytic activity than that of graphene oxide (GO) and its reduced form. The peroxidase catalytic activity of as-obtained few-layer graphene is 45 times higher than that of GO and 4 times higher than that of reduced GO with the same concentration of 30 μg mL−1 and the detection limit of hydrogen peroxide is 10 nM. The excellently catalytic performance can be attributed to the fast electron transfer on the surface of few-layer graphene, which is further confirmed by electrochemical characterization. The as-prepared few-layer graphene has been used to determine hydrogen peroxide in three real water samples with satisfactory results.