Selenium-Functionalized Graphene Oxide That Can Modulate the Balance of Reactive Oxygen Species

Abstract

Graphene oxide (GO) is an important two-dimensional material since it is water-soluble and can be functionalized to adapt to different applications. However, the current covalent functionalization methods usually require hash conditions, long duration, and sometimes even multiple steps, while noncovalent functionalization is inevitably unstable, especially under a physiological environment where competing species exist. Diselenide bond is a dynamic covalent bond and can respond to both redox conditions and visible light irradiation in a sensitive manner. Thus, in this work by combining the stimuli response of diselenide bond and the oxidative/radical attackable nature of GO, we achieved the in situ covalent functionalization of GO simply by stirring GO with diselenide-containing molecules in aqueous solution. The covalent functionalization was proved by Fourier transform infrared, time-of-flight secondary ion mass spectrometry, atomic force microscopy, thermogravimetric analysis, and so forth, and the functionalization mechanism was deduced to involve both redox reaction and radical addition reaction according to the X-ray photoelectron spectrscopy, atomic emission spectroscopy, and Raman spectroscopy. Moreover, we modified GO with a biocompatible diselenide-containing polymer (mPEGSe) and found selenium-functionalized GO could modulate the balance of reactive oxygen species (ROS). GOSe could decrease ROS level by accelerating the reduction of peroxides when the ROS concentration is high while boosting the ROS level by in situ generating ROS when its concentration is relatively low.

Ab Initio Design of Graphene Block Enables Ultrasensitivity, Multimeter‐Like Range Switchable Pressure Sensor

“…As for the rGO/PU and SFrGO/PU foam, the reduction process was different from the rGO foam. Aqueous GO solution (1 mg mL −1 ) and aqueous GO with (HOEG4Se) 2 mixture were prepared. The two kind of solutions were dripped on the PU foam (produced by using a round punch) by using injectors and then sitting these two foams for 2 h. Sodium ascorbate (1 g) was dissolved in water (15 mL) pouring in two small glass bottles, respectively.…”

“…The FTIR spectra of the SFGO and SFrGO foams are presented in Figure b. The specific peak located at ≈2924 cm −1 could be attributed to the CH stretches derived from (HOEG4Se) 2 molecules grafted to GO . Similarly, the OH (≈1339 cm −1 ) bond disappears in the SFrGO foam.…”

Biocatalytic and Antioxidant Nanostructures for ROS Scavenging and Biotherapeutics

“…Similar to the SOD or CAT, GPx is also an essential natural enzyme to sustain the redox equilibrium, which catalyzes the reduction of H 2 O 2 and hydroperoxides into water and alcohols with GSH serving as substrate. [ 98–100 ] GSH, catalyzed by glutathione‐S‐transferases and GPx, is a potent intracellular antioxidant performing as an electron donor to supplement the enzyme's active form. Therefore, the normal redox balance in the body cannot maintain without GSH and GSH‐dependent enzymes, and they are also helpful in cell survival under stress conditions.…”

Reactive Oxygen Species Responsive Polymers for Drug Delivery Systems

“…Subsequently, Xu and Zhang et al developed a series of ROSresponsive selenium-containing polymers for drug delivery. According to the position of the selenide and diselenide bonds in the polymer chain, the polymer could be divided into polymers containing selenium in the main chain (Ma et al, 2010a;Tan et al, 2012;Xia et al, 2017;Zhou et al, 2017), in the side chain (Han et al, 2010;Ren et al, 2012), and in dendritic selenium-containing polymers (Xu et al, 2006;Fu et al, 2012;Li et al, 2016).…”