Green tide biomass templated synthesis of molybdenum oxide nanorods supported on carbon as efficient nanozyme for sensitive glucose colorimetric assay

Abstract

The nanozymes, alternative for natural enzymes, have become popular in many research fields because they exhibit relatively high activity and stability. Herein, we utilize abundant, renewable ocean green tide (Enteromorpha prolifera, EP) waste as a biotemplate to facilely prepare MoO3 nanorods supported on EP derived carbon (MoO3/C). The as-prepared MoO3/C exhibited excellent peroxidase-like activity with Km of 0.13 mM and Vmax of 0.292 μM s−1 (H2O2 as the substrate), superior to most mimetic peroxidases reported so far. The catalytic mechanism of the as-synthesized MoO3/C is proven to be a Ping-pong BiBi electron transfer mechanism. Further, the MoO3/C was used for non-enzymatic measurement of H2O2 sensitively, with the linear H2O2 concentration range of 1–100 μM and a low limit of detection (LOD) of 0.181 μM (S/N = 3). Based on its excellent catalytic activity and stability, the MoO3/C was coupled with glucose oxidase to apply for the colorimetrically sensing glucose sensitively and selectively, with two linear parts, 0.02–0.5 mM as well as 0.5–6.0 mM glucose and a LOD of 10 μM glucose (S/N = 3). Moreover, the detection of blood glucose in real human serums was realized successfully. Thus, the green tide biomass waste templated strategy opens up an avenue to develop nanozymes for many applications, which is simple, cost-effective and environmentally friendly.