Biotemplating of Metal–Organic Framework Nanocrystals for Applications in Small‐Scale Robotics

Abstract

Biotemplating is a powerful approach for manufacturing small-scale devices.Here, the assembly of metal-organic framework (MOF) nanocrystals onto biotemplated magnetic helical structures on the cyanobacterium Spirulina platensis is reported. It is demonstrated that the authors' approach is universal and can be used to equip biotemplated structures with different functional MOF systems. The successful assembly of MOF nanocrystals on magnetically coated helical biotemplates is achieved by decorating the magnetic surface with gelatin, a naturally occurring macromolecule with synthon moieties that allows anchoring of the MOF nanocrystals via electrostatic interactions. Furthermore, as gelatin is a thermally responsive material, it can serve to free the magnetic biotemplates from the MOF nanocrystal cargoes. As such, the systems can be used as highly integrated magnetically driven microrobots with multiple functionalities. To this end, the potential of these composite helical architectures is demonstrated as MOF-based small-scale robots with applications in biomedicine and environmental remediation.

Smart micro- and nanorobots for water purification

“…The majority of micro and nanorobots used for water purification from organic molecules are assessed by their ability to remove or degrade dyes such as methylene blue and rhodamine B 30,[118][119][120] . However, these robots are also effective against more persistent and toxic pollutants, including chemical warfare agents 106 , phenolic 121,122 and nitroaromatic compounds 123,124 , antibiotics 125,126 , hormones 127 and psychoactive sub stances 128 .…”

MoSBOTs: Magnetically Driven Biotemplated MoS2‐Based Microrobots for Biomedical Applications

“…Recently, the helical structure of S. platensis (Sp), an economically accessible cyanobacterium, has been highlighted as an excellent biotemplate for manufacturing helical microrobots. [30][31][32] Here, we adapt our recently described step-wise protocol [33] to synthesize MoSBOTs (Figure 1A) using an S. platensis biotemplate (further experimental details are disclosed in the Experimental Section section). Briefly, S. platensis cells were fixed using a 4% paraformaldehyde solution.…”

Biohybrid Magnetic Microrobots for Tumor Assassination and Active Tissue Regeneration

“…Biomaterials have received increasing attention as the templates for the fabrication of micro-/nanorobots. − Nature has provided a great diversity of unique biomaterials with different structures, which could be utilized to fabricate functional micro-/nanorobots. Natural biomaterials have been used for drug delivery, , controllable manipulation, biosensing, catalysis, environmental remediation, and food chemistry. Pollen grains presented suitable properties for the fabrication of micro-/nanorobots, such as diversity, stability, biocompatibility, and easy accessibility.…”