Biohybrid microrobots with a Spirulina skeleton and MOF skin for efficient organic pollutant adsorption.

Wastewater treatment is a key component in maintaining environmental health and sustainable urban life, and the rapid development of micro/nanotechnology has opened up new avenues for more efficient treatment processes. This work developed a novel biohybrid microrobot for the efficient adsorption of a series of organic pollutants in water-the microrobot with a biodegradable Spirulina skeleton and biocompatible ZIF-8 skin. The microrobot not only has a low-cost and simple preparation method but also shows attractive propulsion in various contaminant solutions (including rhodamine B, methylene blue, and methyl orange) under a low-intensity (3 mT) rotating magnetic field and has excellent directional control. Our research results show that the biohybrid microrobot can significantly improve the adsorption performance of various organic pollutants in the moving state, thereby improving the purification rate. In addition, the microrobot also has good swarming motion control to achieve directional and efficient adsorption of organic pollutants in the microspace. Such Spirulina@ZIF-8 microrobots can be prepared in large quantities as highly controllable, biocompatible, and wireless tools, showing great potential for water treatment.