Colorimetric Detection of Urine Glucose Based ZnFe₂O₄ Magnetic Nanoparticles

TLDR

ZnFe₂O₄ magnetic nanoparticles offer high catalytic efficiency, stability, monodispersity, and rapid separation compared to other peroxidase mimetics and HRP. The authors employed ZnFe₂O₄ MNPs as a colorimetric biosensor that produces a visible TMB oxidation color change for urine glucose detection. The ZnFe₂O₄ MNPs exhibit intrinsic peroxidase‑like activity, enabling a simple, inexpensive, highly sensitive, and selective glucose assay with a linear range of 1.25 × 10⁻⁶–1.875 × 10⁻⁵ mol L⁻¹ and a detection limit of 3.0 × 10⁻⁷ mol L⁻¹.

Abstract

In this paper, we discovered that ZnFe(2)O(4) magnetic nanoparticles (MNPs) possess intrinsic peroxidase-like activity. ZnFe(2)O(4) MNPs exhibit several advantages such as high catalytic efficiency, good stability, monodispersion, and rapid separation over other peroxidase nanomimetics and horseradish peroxidase (HRP). ZnFe(2)O(4) MNPs were used as a colorimetric biosensor for the detection of urine glucose. This method is simple, inexpensive, highly sensitive, and selective for glucose detection using glucose oxidase (GOx) and ZnFe(2)O(4) MNPs with a linear range from 1.25 × 10(-6) to 1.875 × 10(-5) mol L(-1) with a detection limit of 3.0 × 10(-7) mol L(-1). The color change observable by the naked eyes based on the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) is the principle for the sensing of urine glucose level.