Iron-Coordinated L-Lysine-Based Nanozymes with High Peroxidase-like Activity for Sensitive Hydrogen Peroxide and Glucose Detection

It is crucial to develop sensitive and accurate sensing strategies to detect H2O2 and glucose in biological systems. Herein, biocompatible iron-coordinated L-lysine-based hydrogen peroxide (H2O2)-mimetic enzymes (Lys-Fe-NPs) were prepared by precipitation polymerization in aqueous solution. The coordinated Fe2+ ion acted as centers of peroxidase-like enzymes of Lys-Fe-NPs, and the catalytic activity was evaluated via the oxidation of 3,3 & PRIME;,5,5 & PRIME;-tetramethylbenzidine (TMB) by H2O2. Therefore, a sensitive colorimetric detection sensor for H2O2 was constructed with a linear range of 1 to 200 & mu;M and a detection limit of 0.51 & mu;M. The same method could also be applied to highly sensitive and selective detection of glucose, with a linear range of 0.5 to 150 & mu;M and a detection limit of 0.32 & mu;M. In addition, an agarose-based hydrogel biosensor colorimetric was successfully implemented for visual assessment and quantitative detection of glucose. The design provided a novel platform for constructing stable and nonprotein enzyme mimics with lysine and showed great potential applications in biorelevant assays.

Automated summary

Developing sensitive and accurate sensing strategies for detecting H2O2 and glucose in biological systems is crucial. Biocompatible iron-coordinated L-lysine-based hydrogen peroxide (H2O2)-mimetic enzymes (Lys-Fe-NPs) were prepared by precipitation polymerization in aqueous solution. These enzymes showed great potential for colorimetric detection of H2O2 and glucose, with linear ranges and detection limits suitable for biorelevant assays.