Hierarchical Self-Assembly of Responsive Organoplatinum(II) Metallacycle-TMV Complexes with Turn-On Fluorescence

Here we report that the rod-like tobacco mosaic virus (TMV), having a negatively charged surface, can be assembled into three-climensional micrometer-sized bundle-like superstructures via multiple electrostatic interactions with a positively charged molecular "glue", namely, a tetraphenylethylene (TPE)-based discrete organoplatinum(II) metallacycle (TPE-Pt-MC). Due to the nanoconfinement effect in the resultant TMV/TPE-Pt-MC complexes and the aggregation-induced emission (ATE) activity of the TPE units, these hierarchical architectures result in a dramatic fluorescence enhancement that not only provides evidence for the formation of novel metal organic biohybrid materials but also represents an alternative to turn-on fluorescence. Moreover, the dissociation of these final constructs and subsequent release of individual virus have been achieved by disrupting the TPE-Pt-MC core using tetrabutylammonium bromide (TBAB). This strategy is also compatible with other protein-based nanoparticles such as bacteriophage M13 and ferritin, proving the generality of this approach. Hence, this research will open new routes for the fabrication of functional biohybrid materials involving metal organic complexes and anisotropically shaped bionanoparticles.