Synthesis Of Novel Functional Carbon Nanomaterials For Biological Applications

With the development of carbon nanomaterials such as fullerenes,carbon nanotubes and graphene in the application of materials science,nanoelectronics and photonics,their contribution to the biological and biomedical fields also attract great attention.This paper studies the preparation of reduced graphene oxide quantum dots,carbon nitride nanobelts and carbon nitride nanodots and their biological applications.The photodynamic properties before and after reduction of graphene oxide quantum dots were compared,and the mechanism of enhanced photodynamic effect after reduction is discussed.A new "off-on" probe based on carbon nitride nanobelts was prepared,which was used to detect citric acid anion.The assembly of carbon nitride nanodots on single-layer molybdenum disulfide was studied,and antibacterial properties of the prepared product under white light was also explored.In this paper,the main work is divided into the following three aspects:Graphene oxide quantum dots was prepared by ultrasonication-assisted hydrothermal method,which was then chemically reduced with hydrazine hydrate.After reduction,photodynamic effect is twice compared to graphene oxide quantum dots.The enhancement mechanism of photodynamic effects through chemical reduction was deeply discussed.Fluorescent C₃N₄ nanobelts were prepared by alkaline catalytic hydrolysis method.Fluorescent C₃N₄ nanobelts were chelated with the copper ion.Due to the formation of Cu²⁺-C₃N₄ aggregate,the fluorescence of C₃N₄ nanobelts can be quenched by Cu²⁺.After citric acid ion was added,the chelation of C₆H₅O₇^3--Cu²⁺blocked the electron transfer between Cu²⁺and C₃N₄ nanobelts,and the fluorescence of C₃N₄ nanobelts recovered.A new type“off-on”probe based on C₃N₄ nanobelts can be used to rapidly and selectively detect citrate ions with the detection linear range of 1⁴00μM,and the detection limit of 0.78μM.Fluorescent C₃N₄ nanodots were prepared by alkaline catalytic hydrolysis method,which were self-assembled with single-layer MoS₂ to form C₃N₄ nanodots/MoS₂ complex.Due to the thermal effect of MoS₂ and the photodynamic effect of C₃N₄ nanodots,C₃N₄ nanodots-MoS₂ complex can kill bacteria under white light irradiation.After high-temperature calcination under argon atmosphere,the phase of materials was changed to enhance light-activated antibacterial effect.