Work

Fabrication of FeNi@PDA Nanozyme-Driven Dual-Mode Platform for Visual and On-Site Monitoring of Ampicillin

Year: 2026

Type: article

Abstract: The widespread accumulation of ampicillin (AMP) poses significant ecological and health risks, demanding rapid and portable monitoring tools. Herein, a Fe-Ni bimetallic-doped polydopamine (FeNi@PDA) nanozyme with exceptional peroxidase-like activity was synthesized for the visual and on-site monitoring of AMP. Optimized through bimetallic electronic coupling, FeNi@PDA exhibited enhanced catalytic efficiency (KM = 0.051 mmol/L for H₂O₂ and 0.049 mmol/L for TMB) and generated ¹O₂ and ·O₂- via H₂O₂ activation. Leveraging the competitive consumption of reactive oxygen species (ROS) by electron-rich AMP, a colorimetry detection mode was developed where AMP concentration inversely correlated with oxTMB formation. This strategy achieved good linear relationship between 0.05 to 100 μg/mL, with a limit of detection (LOD) of 10.38 ng/mL. Furthermore, a smartphone integrated paper-based detection mode was fabricated by immobilizing FeNi@PDA on filter paper. The color gradient of test papers, analyzed via smartphone imaging, enabled on-site AMP quantification with an LOD of 340 ng/mL. This work not only developed a novel Fe-Ni bimetallic nanozyme with enhanced peroxidase-like activity and established a competitive ROS-consumption sensing mechanism, but also pioneered a dual-mode detection platform for low-cost, user-friendly ampicillin monitoring in environmental samples.

Source: Catalysts

DOI: 10.3390/catal16060489