Ultra-fast colorimetric detection of glutathione by magnetic Fe NPs with peroxidase-like activity

The nanozymes-based sensing platforms have been attracted in recent years due to their outstanding performances in the practical applications. In this work, the magnetic Fe nanoparticles (NPs) with peroxidase-like activity was developed for the fast detection of glutathione (GSH). The Fe NPs were facilely prepared through the reduction of iron trichlorrde hexahydrate (FeCl3 center dot 6H(2)O) by sodium borohydride (NaBH4) at room temperature, exhibiting a merit of simplicity. Significantly, the achieved Fe NPs have high peroxidase-like catalytic activity. At the room temperature, the colorimetric substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) can be rapidly oxidized by Fe NPs with the help of H2O2. After incubated for just 30 s, the catalytic system could achieve a colored solution. Thus, the Fe NPs-based sensing systems can be employed in the development of the colorimetric biosensors with the naked-eye detection.