Synthesis of PB@FePt hybrid nanoparticles with peroxidase-mimicking activity for colorimetric determination of hydrogen peroxide in living cells

Abstract

The rapid determination of H₂O₂ is important in a series of areas, such as bioanalysis, food safety and clinical diagnosis. Here, we describe a novel colorimetric sensing platform, based on Prussian blue nanocubes supporting FePt (PB@FePt HNPs), for the rapid and sensitive determination of H₂O₂. The hybrid nanoparticles exhibited efficient peroxidase-mimicking activities that were verified by the oxidation reaction of 4,4′-bis-2,6-xylidine accompanied with H₂O₂. Under optimized conditions, the linear range for H₂O₂ determination was 20 μM to 800 μM. A relatively low detection limit was acquired reaching 8.27 μM. The principle of these peroxidase-mimicking activities was investigated by the fluorometric spectroscopy method with terephthalic acid as the indicator. Furthermore, the colorimetric sensing platform was successfully utilized to determine the intracellular H₂O₂ in human breast adenocarcinoma (MCF-7) cells. This indicated that the as-constructed PB@FePt-TMB-H₂O₂ system provided a potential approach for H₂O₂ detection in living cells.