Perylene Diimide as a Precise Graphene-like Superoxide Dismutase Mimetic

Abstract

Here we show that the active portion of a graphitic nanoparticle can be mimicked by a perylene diimide (PDI) to explain the otherwise elusive biological and electrocatalytic activity of the nanoparticle construct. Development of molecular analogues that mimic the antioxidant properties of oxidized graphenes, in this case the poly(ethylene glycolated) hydrophilic carbon clusters (PEG–HCCs), will afford important insights into the highly efficient activity of PEG–HCCs and their graphitic analogues. PEGylated perylene diimides (PEGn–PDI) serve as well-defined molecular analogues of PEG–HCCs and oxidized graphenes in general, and their antioxidant and superoxide dismutase-like (SOD-like) properties were studied. PEGn–PDIs have two reversible reduction peaks, which are more positive than the oxidation peak of superoxide (O2•–). This is similar to the reduction peak of the HCCs. Thus, as with PEG–HCCs, PEGn–PDIs are also strong single-electron oxidants of O2•–. Furthermore, reduced PEGn–PDI, PEGn–PDI•–, in the presence of protons, was shown to reduce O2•– to H2O2 to complete the catalytic cycle in this SOD analogue. The kinetics of the conversion of O2•– to O2 and H2O2 by PEG8–PDI was measured using freeze-trap EPR experiments to provide a turnover number of 133 s–1; the similarity in kinetics further supports that PEG8–PDI is a true SOD mimetic. Finally, PDIs can be used as catalysts in the electrochemical oxygen reduction reaction in water, which proceeds by a two-electron process with the production of H2O2, mimicking graphene oxide nanoparticles that are otherwise difficult to study spectroscopically.

Peroxidase‐Like Nanozymes Induce a Novel Form of Cell Death and Inhibit Tumor Growth In Vivo

“…Nanozymes have increasingly attracted significant interest since we first uncovered the intrinsic peroxidase‐like activity of Fe 3 O 4 nanoparticles (NPs) in 2007. [ 3 ] Up to now, there are hundreds of nanomaterials that have been found to mimic the catalytic activity of peroxidases, [ 4,5 ] oxidase, [ 6 ] catalase, [ 7 ] haloperoxidase, [ 8,9 ] monooxygenase, [ 10 ] hydrolase, [ 11,12 ] superoxide dismutase, [ 13,14 ] or multienzyme systems. [ 15,16 ] Along with the rapid development and deepening understanding of nanoscience and nanotechnology, nanozymes hold promise to serve as direct surrogates of traditional enzymes.…”

A long-life lithium-oxygen battery via a molecular quenching/mediating mechanism

“…The PDI-TEMPO reagent was synthesized by reacting 4-amino-2,2,6,6-tetramethylpiperidine with perylene-3,4,9,10-tetracarboxylic dianhydride, followed by an oxidation process (Figure S1a), yielding reddishpurple powders as the nal product. 46,47 The PDI-TEMPO shows a good solubility in common electrolyte solvents used in Li-O 2 batteries, including diethylene glycol dimethyl ether (DEGDME) and dimethyl sulfoxide (DMSO) (Figure S1b). The molecular structures of PDI-TEMPO and intermediates were con rmed by several spectroscopic techniques including ultraviolet-visible spectroscopy (UV-Vis), mass spectrometry (MS), Fourier-transform infrared (FTIR) spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy (Figure S2).…”

“…The conjugated PDI backbone is an e cient electron acceptor to react with O 2 •and can behave as a quencher by quenching the reactivity of O 2 •-. 46 The TEMPO moieties can be electrochemically reduced and oxidized, and therefore can be used as a soluble redox mediator for promoting both discharge and charge reactions in Li-O 2 batteries. The chemical grafting of these moieties via chemical bonds integrates these functionalities in one molecule and enables the intermolecular interactions, which may stabilize these moieties and present individual properties without interference.…”

Recent Progress of Nanozymes in the Detection of Pathogenic Microorganisms

“…Specifically, researchers reported a plenty of carbon-based peroxidase mimics, such as singlewalled carbon nanotubes, [99] graphene oxide (GO), [100][101][102] carbon dots, [103][104][105][106] Fe/N-doped carbon, [107][108][109][110] etc. Other carbon-based nanozymes were studied for their oxidase-like activity including fullerene and its derivatives, [111] C 60 derivatives, [112,113] hydrophilic carbon clusters, [114][115][116] PEGylated perylene diimides, [117] nitrogendoped porous carbon nanospheres, [19] etc. In addition, carbon nitride nanosheets were found to possess both peroxidase-and SOD-like activities.…”