3D hierarchically tubular micromotors with highly selective recognition and capture for antibiotics
Self-propelled micro/nanomotors attract a great deal of attentions from scientific community due to their great potential in environmental and biomedical applications. Here, molecularly imprinted magnetic micromotors with highly selective recognition and capture for antibiotics are present. Such micromotors, powered by local fuel and with precise trajectory control over self-propulsion direction, exhibit unique 3D hierarchically tubular structure constructed by a combination of biomass route and atom transfer radical polymerization (ATRP). Each component of such hierarchical structure performs its own function: Br-MgAl layered double hydroxides (LDH) nanosheets as initiator for ATRP to selectively recognize target molecule, Mn3O4 nanoparticles as catalyst for H2O2 decomposition to generate oxygen bubbles for self-propulsion, and Fe3O4 nanoparticles as magnetic component for magnetic orientation and recycling. Due to the synergetic effects of self-propelled movement and highly exposed selective recognition sites from molecular imprinted LDH nanosheets, such micromotors can rapidly recognize, capture and removal target antibiotic from water. The maximum doxycycline (DC) adsorption capacity of micromotors up to 224.2 mg g-1 in the presence of 2% H2O2, which is 1.6 times greater than its non-micromotor counterparts. More importantly, these micromotors can be quickly recycled by magnetic separation. This study provides a new insight for designing novel molecularly imprinted micromotor for water treatment.