Nanostructured FeS as a mimic peroxidase for biocatalysis and biosensing.

Artificial enzyme mimics have attracted considerable interest due to easy denaturation and leakage of enzymes during their storage and immobilization procedure. Herein we describe the design of a novel mimic peroxidase, a nanostructure of sheet-like FeS prepared by a simple micelle-assisted synthetic method. Such a nanostructure has a large specific surface area and high peroxidase-like activity, and was thus further used as a mimic enzyme for the development of biocatalysts and amperometric biosensors. The sheet-like FeS nanostructure showed typical Michaelis-Menten kinetics and good affinity to both H(2)O(2) and 3,3',5,5'-tetramethyl benzidine. At pH 7.0 the constructed amperometric sensor showed a linear range for the detection of H(2)O(2) from 0.5 to 150 microM with a correlation coefficient of 0.9998 without any electron transfer mediator. The H(2)O(2) sensor based on the sheet-like FeS showed more sensitive response than those based on spherical FeS nanostructure, and resulted in a better stability than horseradish peroxidase when they were exposed to solutions with different pH values and temperatures. These excellent properties made the sheet-like nanostructured FeS powerful tools for a wide range of potential applications as an "artificial peroxidase" as biosensors and biotechnology.