Carbon and graphene quantum dots (CQDs and GQDs), known as zero-dimensional (0D) nanomaterials, have been attracting increasing attention in sensing and bioimaging. Their unique electronic, fluores...

Review of Carbon and Graphene Quantum Dots for Sensing

The advantages conferred by the physical, optical and electrochemical properties of graphene-based nanomaterials have contributed to the current variety of ultrasensitive and selective biosensor devices. In this review, we present the points of view on the intrinsic properties of graphene and its surface engineering concerned with the transduction mechanisms in biosensing applications. We explain practical synthesis techniques along with prospective properties of the graphene-based materials, which include the pristine graphene and functionalized graphene (i.e., graphene oxide (GO), reduced graphene oxide (RGO) and graphene quantum dot (GQD). The biosensing mechanisms based on the utilization of the charge interactions with biomolecules and/or nanoparticle interactions and sensing platforms are also discussed, and the importance of surface functionalization in recent up-to-date biosensors for biological and medical applications.

/pdf/graphene-based-materials-for-biosensors-a-review-3b10ycidtx.pdf

Graphene-Based Materials for Biosensors: A Review.

Nitrogen-doped graphene and graphene quantum dots: A review onsynthesis and applications in energy, sensors and environment.

Synergetic Protective Effect of the Ultralight MWCNTs/NCQDs Modified Separator for Highly Stable Lithium–Sulfur Batteries

Abstract As a new class of fluorescent carbon materials, graphene quantum dots (GQDs) have attracted tremendous attention due to their outstanding properties and potential applications in biological, optoelectronic, and energy-related fields. Herein, top-down and bottom-up strategies for the fabrication of GQDs, mainly containing oxidative cleavage, the hydrothermal or solvothermal method, the ultrasonic-assisted or microwave-assisted process, electrochemical oxidation, controllable synthesis, and carbonization from small molecules or polymers, are discussed. Different methods are presented in order to study their characteristics and their influence on the final properties of the GQDs. The respective advantages and disadvantages of the methods are introduced. With regard to some important or novel methods, the mechanisms are proposed for reference. Moreover, recent exciting progresses on the applications of GQD, such as sensors, bio-imaging, drug carriers, and solar cells are highlighted. Finally, a brief outlook is given, pointing out the issues still to be settled for further development. We believe that new preparation methods and properties of GQDs will be found, and GQDs will play more important roles in novel devices and various applications.

/pdf/synthesis-and-applications-of-graphene-quantum-dots-a-review-2e1fdg4z8w.pdf

Synthesis and applications of graphene quantum dots: a review

High fluorescence quantum yield graphene quantum dots (GQDs) have showed up as a new generation for bioimaging. In this work, luminescent GQDs were prepared by an ameliorative photo-Fenton reaction and a subsequent hydrothermal process using graphene oxide sheets as the precursor. The as-prepared GQDs were nanomaterials with size ranging from 2.3 to 6.4 nm and emitted intense green luminescence in water. The fluorescence quantum yield was as high as 24.6% (excited at 340 nm) and the fluorescence was strongest at pH 7. Moreover, the influences of low-concentration (12.5, 25 μg/mL) GQDs on the morphology, viability, membrane integrity, internal cellular reactive oxygen species level and mortality of HeLa cells were relatively weak, and the in vitro imaging demonstrated GQDs were mainly in the cytoplasm region. More strikingly, zebrafish embryos were co-cultured with GQDs for in vivo imaging, and the results of heart rate test showed the intake of small amounts of GQDs brought little harm to the cardiovascular of zebrafish. GQDs with high quantum yield and strong photoluminescence show good biocompatibility, thus they show good promising for cell imaging, biolabeling and other biomedical applications.

/pdf/synthesis-of-luminescent-graphene-quantum-dots-with-high-ys8kmvd0pd.pdf

Synthesis of Luminescent Graphene Quantum Dots with High Quantum Yield and Their Toxicity Study.

The utility model relates to an experimental biological sample fixing device of a heavy ion irradiation terminal. The experimental biological sample fixing device of the heavy ion irradiation terminal comprises a support base, a support rod, a rotary plate mounted at the upper end of the support rod and driven by a motor to rotate, and a remote controller used for controlling the motor to work, wherein the support base serves as a plate body with a square sliding slot; screw holes corresponding in pairs are formed in one group of opposite inner side surfaces of the square sliding slot; the support rod comprises two longitudinal rods and a horizontal rod; two ends of the horizontal rod are connected with the upper ends of the two longitudinal rods; holes are formed in the lower ends of the two longitudinal rods of the support rod; the lower ends of the two longitudinal rods of the support rod are fixedly connected to the support base by virtue of bolts; a motor is mounted on the horizontal rod of the support rod; three groups of parallel sliding channels which are arranged symmetrically are arranged on the rotary plate; a holder is arranged on each parallel channel. The experimental biological sample fixing device can be used for fixing a plurality of groups of samples once; the real-time remote control is implemented and samples are automatically changed by controlling rotation of the rotary plate; the phenomenon that experimenters enter the irradiation terminal with the ion scattering hidden danger for a plurality of times can be avoided, thereby protecting the experimenters from suffering from body damage.

Bin Liu

Papers

Synthesis of Luminescent Graphene Quantum Dots with High Quantum Yield and Their Toxicity Study.

Experimental biological sample fixing device of heavy ion irradiation terminal