Research On MXene For Peroxide Detection And Radical Scavenging

MXene as the new two-dimensional(2D)transition metal carbides and carbonitrides emerging in 2011,has drawn significant attention from researchers for its excellent properties including great hydrophilicity,high conductivity,large surface area,good photothermal conversion efficiency and electromagnetism.And it has stirred up a new research boom for 2D nanomaterial after graphene.MXene has been extensively applied in the fields of energy storage,batteries,catalysis,sensor,biomedicine et al.Compared with the above-mentioned properties,its feature of easy oxidation is often overlooked and even considered as the shortcoming that hinder the further development of MXene.Until now,little research has been done for exploring the oxidation-reduction characteristic of MXene,and these studies were only concentrated in the fields of batteries and capacitor.There are still no reports of applying this feature to the biomedical field.In order to deepen the understanding of the oxidation-reduction characteristic of MXene and cave the biomedical applications of MXene based on this feature,we carried out a series of work based on the oxidation-reduction characteristic.H₂O₂ and free radicals(FRs),the main endogenous oxidants in organisms,were selected as the representative oxidant to explore the oxidation-reduction property of MXene.Two kinds of MXenes(Ti₃C₂T_x)were synthesized,that is multi-layer MXene and few-layer MXene.The morphology,structure and particle size were characterized by scanning electron microscope(SEM),transmission electron microscope and Malvern Zetasizer.Subsequently,the reaction mechanism between MXene and H₂O₂was investigated.The compositions of the solid products and the gas products produced in this reaction were analyzed by X-ray photoelectron spectroscopy and gas chromatography.Meanwhile,the micro morphology of the reaction process was analyzed by SEM and a corrosion process similar to“drilling”was proposed.Based on the color alteration caused by the reaction,a colorimetric approach was constructed for detection of H₂O₂ using an ultraviolet spectrophotometer,and the limit of detection was 1?mol·L^-1.The colorimetric approach satisfies the precise quantitative demand of H₂O₂ in medical diagnosis.For broadening practical application of the detection strategy,a MXene-enabled test strip was also fabricated in this work,which meets the need of simple and low-cost semi-quantitative detection of H₂O₂ in daily life.Encourged by the scavenging ability of MXene towards H₂O₂,MXene was involved in scavenging various FRs,including a series of reactive oxygen species as well as reactive nitrogen species,and it was proved that MXene processed excellent radical-scavenging activity towards various FRs.In order to further study the scavenging performance of MXene in cells,the cytotoxicity of MXene was verified and H₂O₂was adopted to establish the oxidative damage model of mouse liver 12 cells.Then the model was used to identify the antioxidation capability of MXene for protecting cells from oxidative damage.In summary,the work focused on the oxidation-reduction characteristic of MXene(Ti₃C₂T_x),and two representative oxidants were involved to study this feature.Multiple biomedical application scenarios of MXene based on the oxidation-reduction characteristic were innovatively explored in the work.These findings are expected to promote the development of MXene in nanomedicine and provide a promising direction for expanding the biological application of nanomaterials.