Green Fluorescent Carbon Dots with Critically Controlled Surface States: Make Silk Shine via Feeding Silkworms.

Feeding silkworms with functional materials as additives to produce naturally modified silk is a facile, diverse, controllable, and environmentally friendly method with a low cost of time and investment. Among various additives, carbon dots (CDs) show unique advantages due to their excellent biocompatibility and fluorescence stability. Here, a new type of green fluorescent carbon dots (G-CDs) is synthesized with a high oil-water partition ratio of 147, a low isoelectric point of 5.

Nitrogen-Doped and Sulfonated Carbon Dots as a Multifunctional Additive to Realize Highly Reversible Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (ZIBs) using the Zn metal anode have been considered as one of the next-generation commercial batteries with high security, robust capacity, and low price. However, parasitic reactions, notorious dendrites and limited lifespan still hamper their practical applications. Herein, an eco-friendly nitrogen-doped and sulfonated carbon dots (NSCDs) is designed as a multifunctional additive for the cheap aqueous ZnSO electrolyte, which can overcome the above difficulties effectively.

Mulberry-Leaves-Derived Red-Emissive Carbon Dots for Feeding Silkworms to Produce Brightly Fluorescent Silk.

Fluorescent silk has promising applications in dazzling textiles, biological engineering, and medical products, but the natural Bombyx mori silk has almost no fluorescence. Here carbon dots (CDs) made from mulberry leaves are reported, which have a strong near-infrared fluorescence with absolute quantum yield of 73% and a full width at half maximum of 20 nm. After feeding with such CDs, silkworms exhibit bright red fluorescence, grow healthily, cocoon normally, and turn to moths finally.

In-Situ Growth of Mn O Nanoparticles on Nitrogen-Doped Carbon Dots-Derived Carbon Skeleton as Cathode Materials for Aqueous Zinc Ion Batteries.

Mn O is a promising cathode material for aqueous zinc ion batteries (ZIBs) which is a new type of low cost, eco-friendly, high security energy storage system, while those previously reported electrochemical capacities of Mn O are far from its theoretical value. In this work, Mn O nanoparticles and nitrogen-doped carbon dots (NCDs) are synthesized together through an in-situ hydrothermal route, and then calcined to be a nanocomposite in which Mn O nanoparticles are anchored on a nitrogen-doped carbon skeleton (designated as Mn O /NCDs). Although the carbon content is only 3.

Red Fluorescent Carbon Dot Powder for Accurate Latent Fingerprint Identification using an Artificial Intelligence Program.

Development and comparison of the latent fingerprints (LFPs) are two major studies in detection and identification of LFPs, respectively. However, integrated research studies on both fluorescent materials for LFP development and digital-processing programs for LFP comparison are scarcely seen in the literature. In this work, highly efficient red-emissive carbon dots (R-CDs) are synthesized in one pot and mixed with starch to form R-CDs/starch phosphors.

Efficient Oxygen Electrocatalyst for Zn-Air Batteries: Carbon Dots and CoS Nanoparticles in a N,S-Codoped Carbon Matrix.

Non-noble metal-based bifunctional electrocatalysts for both oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) are an essential component of high-performance rechargeable Zn-air batteries (ZABs). Herein, we report a novel and simple method for preparing CoS nanoparticles embedded in N and S codoped carbon materials with aid of carbon dots (CDs). CDs play a key role in distributing CoS nanoparticles in the matrix uniformly and enhancing the specific surface area and the electric conductivity simultaneously.

Robust Negative Electrode Materials Derived from Carbon Dots and Porous Hydrogels for High-Performance Hybrid Supercapacitors.

Hybrid supercapacitors generally show high power and long life spans but inferior energy densities, which are mainly caused by carbon negative electrodes with low specific capacitances. To improve the energy densities, the traditional methods include optimizing pore structures and modifying pseudocapacitive groups on the carbon materials. Here, another promising way is suggested, which has no adverse effects to the carbon materials, that is, constructing electron-rich regions on the electrode surfaces for absorbing cations as much as possible.

Heteroatom-doped carbon dots based catalysts for oxygen reduction reactions.

Carbon materials doped with heteroatoms are a class of cost-effective and stable electrocatalysts for oxygen reduction reactions (ORR), whose activities are mainly based on the heteroatom-related active sites. Besides the widely reported one-dimensional carbon nanotubes and two-dimensional graphene materials, carbon dots (CDs), as a new kind of zero-dimensional carbon materials, exhibit a range of unique structures and promising catalytic activities for ORR. In order to optimize the complex conditions of carbon-based catalysts, composites consisting of doped CDs and reduced graphene oxide (rGO) (designated as CD/rGO) are prepared hydrothermally, in comparison with directly doped rGO.

Solvent-Controlled Synthesis of Highly Luminescent Carbon Dots with a Wide Color Gamut and Narrowed Emission Peak Widths.

Carbon dots (CDs) have tremendous potential applications in bioimaging, biomedicine, and optoelectronics. By far, it is still difficult to produce photoluminescence (PL) tunable CDs with high quantum yield (QY) across the entire visible spectrum and narrow the emission peak widths of CDs close to those of typical quantum dots. In this work, a series of CDs with tunable emission from 443 to 745 nm, quantum yield within 13-54%, and narrowed full width at half maximum (FWHM) from 108 to 55 nm, are obtained by only adjusting the reaction solvents in a one-pot solvothermal route.

Highly Efficient Red-Emitting Carbon Dots with Gram-Scale Yield for Bioimaging.

Carbon dots (CDs) are a new class of photoluminescent (PL), biocompatible, environment-friendly, and low-cost carbon nanomaterials. Synthesis of highly efficient red-emitting carbon dots (R-CDs) on a gram scale is a great challenge at present, which heavily restricts the wide applications of CDs in the bioimaging field. Herein, R-CDs with a high quantum yield (QY) of 53% are produced on a gram scale by heating a formamide solution of citric acid and ethylenediamine.

Facile synthesis of red-emitting carbon dots from pulp-free lemon juice for bioimaging.

In this work, red-emitting carbon dots (R-CDs) with a high quantum yield (QY) of 28% in water were synthesized for the first time by heating an ethanol solution of pulp-free lemon juice. The obtained R-CDs were mono-dispersed with an average diameter of 4.6 nm, and exhibited excitation-independent emission at 631 nm.

Self-Assembled ZnO Nanoparticle Capsules for Carrying and Delivering Isotretinoin to Cancer Cells.

ZnO@polymer core-shell nanoparticles are assembled into novel capsule shells with diameters of about 100 nm to load isotretinoin (ISO) with a capacity as high as 34.6 wt %. Although ISO, a widely used drug for acne treatment, by itself is not suitable for treating cancer because of its hydrophobicity, our ZnO-ISO composite showed much stronger anticancer activity.

Red-Emissive Carbon Dots for Fingerprints Detection by Spray Method: Coffee Ring Effect and Unquenched Fluorescence in Drying Process.

Brightly red fluorescent carbon dots are synthesized hydrothermally and dissolved in diluted hydrochloric acid solution. Such carbon dots exhibit excitation-independent emission at about 620 nm with quantum yield over 10%, which is visible in daylight. After the carbon dots solution is sprayed to the fingerprints on various solid substrates and dried in air, clear fingerprints can be seen under an ultraviolet lamp and stay stable for 1 day.

Carbon Dots/NiCo O Nanocomposites with Various Morphologies for High Performance Supercapacitors.

A series of carbon dots/NiCo O composites with various morphologies are prepared and tested for supercapacitors. These samples have good electrical conductivities and efficient ions transport paths, so they exhibit high specific capacitances, superior rate performances, and high cycling stabilities. The optimal composite for hybrid supercapacitor exhibits a high energy density up to 62.

ZnO-Based Nanoplatforms for Labeling and Treatment of Mouse Tumors without Detectable Toxic Side Effects.

ZnO quantum dots (QDs) were synthesized with polymer shells, coordinated with Gd(3+) ions and adsorbed doxorubicin (DOX) together to form a new kind of multifunctional ZnO-Gd-DOX nanoplatform. Such pH sensitive nanoplatforms were shown to release DOX to cancer cells in vitro and to mouse tumors in vivo, and reveal better specificity and lower toxicity than free DOX, and even better therapeutic efficacy than an FDA approved commercial DOX-loading drug DOX-Liposome Injection (DOXIL, NDA#050718). The ZnO-Gd-DOX nanoplatforms exhibited strong red fluorescence, which benefited the fluorescent imaging on live mice.

Full-Color Light-Emitting Carbon Dots with a Surface-State-Controlled Luminescence Mechanism.

Carbon dots (CDs) with tunable photoluminescence (PL) and a quantum yield of up to 35% in water were hydrothermally synthesized in one pot and separated via silica column chromatography. These separated CDs emitted bright and stable luminescence in gradient colors from blue to red under a single-wavelength UV light. They exhibited high optical uniformity; that is, every sample showed only one peak in the PL excitation spectrum, only one peak in the excitation-independent PL emission spectrum, and similar monoexponential fluorescence lifetimes.

Folic acid functionalized ZnO quantum dots for targeted cancer cell imaging.

Aqueous stable luminescent ZnO quantum dots (QDs) were successfully synthesized with primary amine groups on the surface, which were designed to conjugate with folic acid (FA) to produce the final ZnO-FA QDs. Such ZnO-FA QDs were able to target some specific cancer cells with overexpressed FA receptors on the membranes and thus differentiate the MCF-7 cancer cells from the normal 293T cells. The nanoparticle uptaking experiments by different cells were carried out in parallel and tracked by confocal laser microscopy dynamically.

Hierarchical porous carbon materials with high capacitance derived from Schiff-base networks.

A type of hierarchical porous carbon material was prepared using a Schiff-base network as the precursor and ZnCl2 as the activation agent, and their electrochemical performances were investigated in acid and alkaline aqueous solutions, respectively. The as-prepared materials have high surface areas, appropriate distributions of hierarchical pore sizes, and various forms of nitrogen/oxygen derivatives. These structural advantages guarantee the outstanding performances of such carbon materials as electrodes for supercapacitors, which include high specific capacitances, fast current responses, and high cycling stabilities.

Nitrogen and sulfur co-doped carbon dots with strong blue luminescence.

Sulfur-doped carbon dots (S-CDs) with a quantum yield (QY) of 5.5% and nitrogen, sulfur co-doped carbon dots (N,S-CDs) with a QY of 54.4% were synthesized, respectively, via the same hydrothermal route using α-lipoic acid as the carbon source.

In situ tracking the intracellular delivery of antisense oligonucleotides by fluorescein doped silica nanoparticles.

Antisense oligonucleotides (ASOs) are often utilized to interfere with gene expression at mRNA level for cancer treatment. Here, we synthesized fluorescein doped silica nanoparticles (FSNPs) and coated them by polyethyleneimine (PEI) for carrying ASOs. Agarose gel electrophoresis proved that PEI/FSNPs could load ASOs by a weight ratio as high as 30:1.

Nitrogen-doped carbon dots derived from polyvinyl pyrrolidone and their multicolor cell imaging.

Nitrogen-doped carbon dots (N-CDs) with a high quantum yield of 19.6% were prepared by calcining polyvinyl pyrrolidone (PVP, K-30), and then modified with 4,7,10-trioxa-1,13-tridecanediamine. The as-prepared N-CDs exhibited excitation-dependent and pH-sensitive photoluminescence.

ZnO nanoparticles applied to bioimaging and drug delivery.

The last decade has seen significant achievements in biomedical diagnosis and therapy at the levels of cells and molecules. Nanoparticles with luminescent or magnetic properties are used as detection probes and drug carriers, both in vitro and in vivo. ZnO nanoparticles, due to their good biocompatibility and low cost, have shown promising potential in bioimaging and drug delivery.

One-pot synthesis of water-dispersible Ag2S quantum dots with bright fluorescent emission in the second near-infrared window.

The second near-infrared window (NIR-II, wavelength of 1.0-1.4 μm) is optimal for the bioimaging of live animals due to their low albedo and endogenous autofluorescence.

Stable photoluminescent ZnO@Cd(OH)2 core-shell nanoparticles synthesized via ultrasonication-assisted sol-gel method.

Core-shell structured ZnO@Cd(OH)(2) nanoparticles with stable and improved luminescence have been prepared successfully via a facile ultrasonication-assisted sol-gel method. Their composition and structure have been confirmed by high resolution transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and infrared spectra. The size of the nanoparticles decreases gradually along with the increase in the shell thickness, indicating that Cd(OH)(2) shells can hider ZnO cores growth and aggregation effectively.