β-AgVO3 Nanorods as Peroxidase Mimetic for Colorimetric Determination of Glucose

beta-AgVO3 nanorods have been demonstrated to exhibit intrinsic peroxidase-like activity. The oxidation of glucose can be catalyzed by glucose oxidase (GOx) to generate H2O2 in the presence of O-2. The beta-AgVO3 nanorods can catalytically oxidize peroxidase substrates including o-phenylenediamine (OPD), 3,3',5,5'-tetramethylbenzidine (TMB), and diammonium 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) by H2O2 to produce typical color reactions: OPD from colorless to orange, TMB from colorless to blue, and ABTS from colorless to green. The catalyzed reaction by the beta-AgVO3 nanorods was found to follow the characteristic Michaelis-Menten kinetics. Compared with horseradish peroxidase and AgVO3 nanobelts, beta-AgVO3 nanorods showed a higher affinity for TMB with a lower Michaelis-Menten constant (K-m) value (0.04118 mM) at the optimal condition. Taking advantage of their high catalytic activity, the as-synthesized beta-AgVO3 nanorods were utilized to develop a colorimetric sensor for the determination of glucose. The linear range for glucose was 1.25-60 mu M with the lower detection limit of 0.5 mu M. The simple and sensitive GOx-beta-AgVO3 nanorods-TMB sensing system shows great promise for applications in the pharmaceutical, clinical, and biosensor detection of glucose.