Photocatalytic properties of thin films of ruthenium metallopolymers/gold nanoparticle: Polyoxometalate composites using visible excitation

Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle have been deposited onto electrodes using two separate methods, alternate immersion layer-by-layer assembly and pre-assembled drop-casting; PVP is poly(4-vinylpyridine), BPY is 2,2'-bipyridyl, and DMAP is 4-dimethylaminopyridine. Significantly, the efficiency of the photocatalysis depends markedly on the structure of the [RuPVP-AuNP:POM] even when photonic properties are very similar. Strikingly, despite their similar photonic properties, an additional optical transition is observed in UV-vis and the Raman spectra of pre-assembled drop cast [RuPVP-AuNP:POM], which was not seen in dip coated [RuPVP-AuNP:POM]. Importantly, this electronic communication enhances the photocatalytic oxidation of benzaldehyde by a factor of more than four. While there is clear evidence for photosensitisation in the drop cast not present for the dip coated systems, the magnitude of the photocurrent, i.e.,(82.2 6.6) nA·cm 2for pre-assembled drop cast [RuPVP-AuNP:POM] at a ruthenium to Au nanoparticle mole ratio of 48:1, is twice as large as that those found in [Ru-PVP:POM] film.

Supramolecular metallopolymer for hypoxia-activated ruthenium complexes delivery and smart chemo-photodynamic therapy

The Ru complexes have garnered a great deal of attention for antitumor phototherapy;however, achieving efficient cellular uptake and tumor-specific activation represents a major challenge. Herein, we synthesize a hypoxia-activated Ru complex(Ru ANM) and construct it into supramolecular polymers(Poly Ru ANM) through high binding affinity interaction. The amphiphilic supramolecular polymers possess self-assembly, resulting in the formation of diverse nanostructures exhibiting a range of morphologies by simply adjusting the host-guest ratio. As the polymer nanostructure size and morphology have been optimized, Poly Ru ANM prevents premature drug leakage and accumulates rapidly in the tumor cells. In the tumor hypoxia microenvironment, the polymer undergoes selective activation and disintegration, leading to the unlock of Ru complexes.Notably, the subsequent application of red light irradiation exacerbates the hypoxia and potentiates the liberation of the Ru complexes. This polymer design concept provides some novel insights into on-demand drug delivery and smart chemophotodynamic therapy.

Light-mediated CO_(2)-responsiveness of metallopolymer microgels

Here, we report a finding on light-mediated CO_(2)^(-)responsiveness. It is found on the microgels that are made of side-chain type metallopolymers containing metalla-aromatics. Turbidity and laser light scattering studies on dilute aqueous dispersion of these microgels in dark indicate high CO_(2)^(-)responsivity, but poor reversibility upon N2 purge, which can be improved by exposing to light. This light-mediated CO_(2)^(-)responsiveness can be elucidated by the loss of aromaticity from initial photoexcitation and concurrent formation of a less reactive, antiaromatic excited state of relatively low CO_(2) binding affinity, and by subsequent relief of antiaromaticity that can enhance the CO_(2) removal. The finding is also checked by CO_(2) uptake-release experiments on the microgels, which enables both CO_(2) capture of high capacity and CO_(2) removal of good reversibility under a mild condition, allowing effective and reversible response to dilute CO_(2).

Antifouling and antimicrobial cobaltocenium-containing metallopolymer double-network hydrogels

Compared with single-network hydrogels,double-network hydrogels offer higher mechanical strength and toughness.Integrating useful functions into double-network hydrogels can expand the portfolios of the hydrogels.We report the preparation of double-network metallopolymer hydrogels with remarkable hydration,antifouling,and antimicrobial properties.These cationic hydrogels are composed of a first network of cationic cobaltocenium polyelectrolytes and a second network of polyacrylamide,all prepared via radical polymerization.Antibiotics were further installed into the hydrogels via ion-complexation with metal cations.These hydrogels exhibited significantly enhanced hydration,compared with polyacrylamide-based hydrogels,while featuring robust mechanical strength.Cationic metallopolymer hydrogels exhibited strong antifouling against oppositely charged proteins.These antibiotic-loaded hydrogels demonstrated a synergistic effect on the inhibition of bacterial growth and antifouling of bacteria,as a result of the unique ion complexation of cobaltocenium cations.