Pt and ZnFe₂O₄ Nanoparticles Immobilized on Carbon for the Detection of Glutathione

The catalytic activity of nanozymes has attracted much attention in biochemical analyses and the antibiosis and environmental fields. However, easy aggregation and difficulty in recycling greatly result in a decrease of their catalytic activity and further restrict their practical application. Herein, we immobilized Pt and ZnFe₂O₄ nanoparticles on poplar-wood-derived carbon (ZnFe₂O₄/C), which exhibited excellent peroxidase-like activity and high affinity toward H₂O₂ and 3,3′,5,5′-tetramethylbenzidine (TMB). Moreover, it could be easily separated by an external magnetic force from the reaction system. A sensitive and selective colorimetric sensor for glutathione (GSH) was established based on Pt/ZnFe₂O₄/C nanoperoxidase. The linear range for GSH was from 1 to 30 μM, and the limit of detection for GSH was calculated as 0.38 μM. The colorimetric method was applied to determine GSH in real samples for injection.