Hemin-functionalized WS2 nanosheets as highly active peroxidase mimetics for label-free colorimetric detection of H2O2 and glucose.
Hemin-functionalized WS2 nanosheets (hemin/WS2-NSs) were first obtained by hemin assembled on the surface of few-layered WS2 nanosheets (WS2-NSs) via van der Waals interactions. Significantly, this new material possessed the advantages of both hemin and WS2 nanosheets and exhibited some unique properties. Firstly, hemin/WS2-NSs had intrinsic peroxidase-like activity, which could effectively catalyze oxidation of the substrate 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 to produce a typical blue colored reaction. Secondly, the activity of hemin/WS2-NSs was much higher than the activity of hemin or WS2-NSs alone. The catalytic activity followed the typical Michaelis-Menten kinetics and was dependent on the temperature, pH, H2O2 concentration, as well as reaction time. Based on this finding, a new highly sensitive and selective colorimetric method for H2O2 and glucose detection was developed. This method was simple and inexpensive for glucose detection using glucose oxidase (GOx) and hemin/WS2-NSs with a linear range of 0.5 × 10(-5) to 2.0 × 10(-4) mol L(-1) with a detection limit of 1.5 × 10(-6) mol L(-1). The good catalytic activity and low-cost make the hemin/WS2-NSs a useful biocatalyst for a wide range of potential applications in environmental chemistry, biotechnology and clinical diagnostics.
Key Laboratory of Chemistry of Northwestern Plant Resources, Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China. hdqiu@licp.cas.cn.
Qiao
Q
Chen
Jia
J
Chen
Cunji
C
Gao
Mingliang
M
Zhang
Junying
J
Chen
Hongdeng
H
Qiu
D001560:Benzidines / Q000737:chemistry; D040761:Biomimetic Materials / Q000737:chemistry*; D003124:Colorimetry / Q000379:methods*; D004220:Disulfides / Q000737:chemistry*; D005947:Glucose / Q000032:analysis*; D006427:Hemin / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D007700:Kinetics; D049329:Nanostructures / Q000737:chemistry*; D009195:Peroxidase / Q000378:metabolism*; D014414:Tungsten / Q000737:chemistry*
D001560:Benzidines; D004220:Disulfides; C021758:3,3',5,5'-tetramethylbenzidine; D006427:Hemin; D006861:Hydrogen Peroxide; D009195:Peroxidase; D005947:Glucose; D014414:Tungsten