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

Abstract

β‐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 O2. The β‐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 β‐AgVO3 nanorods was found to follow the characteristic Michaelis–Menten kinetics. Compared with horseradish peroxidase and AgVO3 nanobelts, β‐AgVO3 nanorods showed a higher affinity for TMB with a lower Michaelis–Menten constant (Km) value (0.04118 mM) at the optimal condition. Taking advantage of their high catalytic activity, the as‐synthesized β‐AgVO3 nanorods were utilized to develop a colorimetric sensor for the determination of glucose. The linear range for glucose was 1.25–60 μM with the lower detection limit of 0.5 μM. The simple and sensitive GOx‐β–AgVO3 nanorods–TMB sensing system shows great promise for applications in the pharmaceutical, clinical, and biosensor detection of glucose.

DiZyme: Open‐Access Expandable Resource for Quantitative Prediction of Nanozyme Catalytic Activity

“…To address the need for synthesis‐by‐design approach in nanozymes development, a comprehensive database (Figure S1, Supporting Information) of >300 metal‐, bimetal‐, metal‐oxide, and nanozymes of total 67 individual compositions (Figure S2, Supporting Information) with peroxidase, oxidase and catalase activities, consisting of its fundamental element parameters as well as physicochemical characterization of nanomaterials was manually collected from >100 articles with valid data representation, material characterization, and measured activity, [ 18–20,22,30–35,54–145 ] as well as the databases with elemental properties (Table S1, Supporting Information). Catalytic activity expressed as Michaelis–Menten constant ( K m , mM) is the substrate concentration required to achieve half the maximum enzyme rate, the catalytic rate constant ( K cat , s −1 ) is the number of turns‐number of substrate molecules that each nanozyme (which concentration is expressed in µg mL −1 ) site converts into product per unit time, considering reaction rate ( V max , mM s −1 ) and the weight‐to‐volume concentration of catalyst (µg mL −1 ).…”