Figure 4.

Pb (II) ions decontamination by GOx-microbots and characterization of microbots after decontamination. (A) Decontamination of Pb(II) ions in different systems: In the presence of (a) H₂O₂ (1.5% v/v) and of SDS (0.1% w/v) after 24 h, (b) SDS (0.1% w/v) and nonmotile GOx- microbots after 1 h, (c) SDS (0.1% w/v) and GOx-microbots stirred by external magnets after 1 h, (d) H₂O₂ (1.5% v/v), SDS (0.1% w/v) and docked GOx-microbots after 1 h (immobilized by stationary magnetic field), and (e) in the presence of H₂O₂ (1.5% v/v) and SDS (0.1% w/v) motile GOx-microbots after 1 h. (B) Decontamination of Pb(II) ions for different concentrations of GOx-microbots after 1 h in the presence of H₂O₂ (1.5% v/v) and of SDS (0.1% w/v). (Inset: ICP-OES signal of lead concentration after 1 h of decontamination process for increasing amount of motors.) (C) EDX mapping: the SEM image of the analyzed GOx-microbot after the decontamination process showing, carbon distribution, platinum distribution, and Pb(II) distribution.