Size-controllable amine-functionalized graphene quantum dots (GQDs) are prepared by an eco-friendly method with graphene oxide sheets, ammonia and hydrogen peroxide as starting materials. Using a Sephadex G-25 gel column for fine separation, for the first time we obtain GQDs with either single or double layers. By atomic force microscopy characterization, we confirm that hydrogen peroxide and ammonia play a synergistic role on graphene oxide (GO), in which the former cuts the GO into small pieces and the latter passivates the active surface to give amine-modified GQDs. Due to the low cytotoxicity and excellent biocompatibility of the obtained amine-functionalized GQDs, besides the multiwavelength imaging properties of GQDs, for the first time we find that this kind of GQD exhibits good antimycoplasma properties. Given the superior antimycoplasma effect of the GQDs and their eco-friendly mass production with low cost, these new GQDs may offer opportunities for the development of new antimycoplasma agents, thus extending their widespread application in biomedicine.

The poly(maleic anhydride‐alt‐1‐octadecene‐poly(ethylene glycol)) (C18PMH‐PEG) modified single‐walled carbon nanohorns (SWNHs) are designed with high stability and biocompatibility. The as‐prepared SWNHs/C18PMH‐PEG not only can serve as an excellent photothermal agent but also can be used as a promising photoacoustic imaging (PAI) agent both in vitro and in vivo due to its strong absorption in the near infrared (NIR) region. The PAI result reveals that the SWNHs/C18PMH‐PEG possesses ultra long blood circulation time and can significantly be accumulated at the tumor site through the enhanced penetration and retention (EPR) effect. The maximum accumulation of SWNHs/C18PMH‐PEG at tumor site could be achieved at the time point of 24 h after intravenous injection, which is considered to be the optimal time for the 808 nm laser treatment. The subsequent photothermal ablation of tumors can be achieved without triggering any side effects. Therefore, a PAI guided PTT platform based on SWNHs is proposed and highlights the potential theranostic application for biomedical uses.

Photodynamic therapy (PDT) is an excellent therapeutic modality for various malignant and nonmalignant cancers. This approach utilizes reactive oxygen species generated through the reaction between photosensitizer and oxygen in tissues upon light irradiation to achieve effective treatment. However, limited penetration depth and oxygen-deficient microenvironment hinder the efficiency of PDT. In this work, we design a multifunctional near-infrared (NIR)-triggered theranostic agent based on upconversion-nanoparticles-Polyoxyethylene bis (amine)-trismethylpyridylporphyrin-fullerene nanocomposite (UCNP-PEG-FA/ PC 70 ) for imaging (fluorescence/upconversion luminescence/magnetic resonance imaging)-guided photodynamic therapy. In this multimodal nanocompsite, UCNPs are employed as light transducers to convert NIR light into ultraviolet-visible light to activate PC 70 to generate singlet oxygen ( 1 O 2 ) even under low-oxygen conditions. Meanwhile, the upconversion emission, magnetic resonance imaging and fluorescence signal coming from UCNPs and PC 70 nanocomposite enable UCNP-PEG-FA/PC 70 to act as a multimodal imaging diagnostic agent, which facilitates the imaging-guided PDT. Furthermore, folate-mediated active targeting would enhance the accumulation of multifunctional hybrid in tumor. In vitro as well as in vivo results suggest that this smart nanocomposite is promising as an NIR light-triggered and -targeted theranostic platform for imaging-guided PDT of cancer, which may provide a solution to the bottleneck problems of PDT, namely, limited penetration depth and oxygen-deficient microenvironment.

Covalent organic frameworks (COFs) with porphyrins as structural units are a new kind of porous organic polymers, which have a regular and ordered structure, abundant porosity, and good stability. In the past, the construction of porphyrin COFs was generally synthesized by routes such as a Schiff base reaction. Here, we report a new COF structure by linking the porphyrin with the triazine ring. Using a cyano group-terminated porphyrin as a structural unit precursor, a new triazine-porphyrin hyperconjugated COF (TA-Por-sp2-COF) was constructed through the cyano group’s self-polymerization. The extension of porphyrin units in two directions that stemmed from the cyano group at para-positions accounts for the establishment of a highly ordered two-dimensional topological structure. Attributing to the collaboration of electron-donating and withdrawing blocks for photo-induced carrier separation and adequate porosity for mass diffusion, this hyperconjugated system showed high photocatalytic performance in organic reactions such as the aerobic coupling reaction of benzylamine and thioanisole selective oxidation.

The synthesis of crystalline polymer with a well-defined orientated state and a two-dimensional crystalline size beyond a micrometer will be essential to achieve the highest physical feature of polymer material but remain challenging. Herein, we show the synthesis of the crystalline unipolymer monolayer with an unusual ultrahigh modulus that is higher than the ITO substrate and high conductance by simultaneous electrosynthesis and manipulation. We find that the polymer monolayer has fully extended in the vertical and unidirectional orientation, which is proposed to approach their theoretically highest density, modulus, and conductivity among all aggregation formations of the current polymer. The modulus and current density can reach 40 and 1000 times higher than their amorphous counterpart. It is also found that these monolayers exhibit the bias-and length-dependent multiple charge states and asymmetrically negative differential resistance (NDR) effect, indicating that this unique molecular tailoring and ordering design is promising for multilevel resistive memory devices. Our work demonstrates the creation of a crystalline polymer monolayer for approaching the physical limit of polymer electronic materials and also provides an opportunity to challenge the synthetically iterative limit of an isolated ultra-long polymer.

Macromolecular magnetic resonance imaging (MRI) contrast agent Gd-DTPA-HSA (DTPA, diethylene triamine pentacetate acid; HSA, human serum albumin) as a model has been successfully conjugated with trimalonic acid modified C60 for contrast enhancement at clinically used magnetic field strength. The Gd-DTPA-HSA-C60 conjugate exhibit maximal relaxivity (r1 = 86 mM(-1) s(-1) at 0.5 T, 300 K) reported so far, which is much superior to that of the control Gd-DTPA-HSA (r1 = 38 mM(-1 )s(-1)) under the same condition and comparable to the theoretical maximum (r1 = 80-120 mM(-1) s(-1), at 20 MHz and 298 K), indicating the synergistic effect of HSA and carboxylfullerene on the increased contrast enhancement. TEM characterization reveals that both Gd-DTPA-HSA-C60 and Gd-DTPA-HSA can penetrate the cells via endocytosis and trans-membrane, respectively, suggesting the potential to sensitively image the events at the cellular and subcellular levels. In addition, the fusion of fullerene with Gd-DTPA-HSA will further endow the resulting complex with photodynamic therapy (PDT) property and thus combine the modalities of therapy (PDT) and diagnostic imaging (MRI) into one entity. More importantly, the payloaded Gd-DTPA may substitute for other more stable Gd-DOTA and HSA as a theranostic package can further work as a drug delivery carrier and effectively control drug release through proteolysis.

An efficient and facile synthesis method of nitrogen-doped mesoporous graphitic carbon (NMGC) was reported with melamine as a nitrogen source and citric acid as a carbon source. By taking advantage of the functional groups on melamine and citric acid, a uniform mixture of these two components was obtained via a self-assembly process. Accordingly, the nitrogen-doped mesoporous graphitic carbon (NMGC) can be obtained by means of the high temperature treatment. This as-prepared NMGC showed a promising potential as an anode material in lithium-ion batteries.

The construction of core-shell structures through surface coating, and then making use of the synergistic effects between the core and shell to design and synthesize heterogeneous catalysts is a hot topic in the heterogeneous catalysis field. Developing a general coating route with functional shell materials is further highly desirable. Here we found that a poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) (PZS) layer can be generally coated on various substrates with different components and morphologies, including metal oxides, noble metal nanoparticles, carbon materials and metal-organic frameworks (MOFs). In addition, the coating thickness could be well controlled through simply adjusting the amount of monomers. Taking advantage of the heteroatoms in the PZS layer and the synergistic effect between the core and shell, new methods for fabrication of co-doped hollow carbon shell catalysts and transition metal phosphide nanoparticles were developed. As a proof-of-concept application, the N, P, S-doped hollow carbon shells prepared by calcination of a ZnCo-ZIFs@PZS core-shell structure could act as a good carbo-catalyst for selective oxidation of C-H bonds in water.