V2O5-montmorillonite nanocomposites of peroxidase-like activity and their application in the detection of H2O2 and glutathione

In this work, montmorillonite, a traditional layered mineral, the surface of which was modified was further applied in biological detection. Specifically, a novel composite (V2O5-Mt) composed of V2O5 nanoparticles an-chored on montmorillonite was synthesized by a simple method. The V2O5-Mt possessed the enhanced perox-idase-like activity, proved by evaluating the catalysis of 3 ',3 ',5 ',5 '-tetramethylbenzidine (TMB) oxidized by H2O2, accompanied by a visual change of color. Furthermore, the more the H2O2 content, the deeper the color changed. On the basis of this, a novel colorimetric platform for detecting H(2)O(2)was established with the linear range and the limit of detection was found to be 30 to 400 mu M and 4.0 mu M, respectively. The peroxidase-like activity of V2O5-Mt is in accord with Michaelis-Menten kinetics. The fluorescent probe experiments verified that the catalytic activity of V2O5-Mt was attributed to the acceleration of electrons transfer among V2O5-Mt, TMB, and H2O2, which was promoted by the vanadium valence state changes between V and IV. The sensing platform was also successfully applied to detect H2O2 in real samples. Furthermore, a colorimetric sensing platform was established to detect glutathione with the linear range and limit of detection to be 0.1-30 mu M and LOD = 0.069 mu M, respectively.