Highly regulated core-shell Fe(3)O(4)-poly(3, 4-ethylenedioxythiophene) (PEDOT) microspheres were successfully synthesized by a two-step method in the presence of polyvinyl alcohol (PVA) and p-toluenesulfonic acid (p-TSA). And their morphology, microstructure, electromagnetic and microwave absorbing properties were subsequently characterized. By simply adjusting the molar ratio of 3, 4-ethylenedioxythiophene (EDOT) to Fe(3)O(4) (represented by (EDOT)/(Fe(3)O(4))), the thickness of the polymer shell can be tuned from tens to hundreds of nanometers. Moreover, it was found that the composite exhibited excellent microwave absorbing property with a minimum reflection loss (RL) of about -30 dB at 9.5 GHz with a (EDOT)/(Fe(3)O(4)) ratio of 20.

Carbon dots (CDs) have potentials to be utilized in optoelectronic devices, bioimaging, and photocatalysis. The majority of the current CDs with high quantum yield to date were limited in the blue light emission region. Herein, on the basis of surface electron-state engineering, we report a kind of CDs with reversible switching ability between green and red photoluminescence with a quantum yield (QY) of both up to 80%. Highly efficient green and red solid-state luminescence is realized by doping CDs into a highly transparent matrix of methyltriethoxysilane and 3-triethoxysilylpropylamine to form CDs/gel glasses composites with QYs of 80 and 78%. The CDs/gel glasses show better transmittance in visible light bands and excellent thermal stability. A blue-pumped CDs/gel glasses phosphor-based trichromatic white light-emitting diode (WLED) is realized, whose color rendering index is 92.9. The WLED gets the highest luminous efficiency of 71.75 lm W in CDs-based trichromatic WLEDs. This work opens a door for developing highly efficient green- and red-emissive switching CDs which were used as phosphors for WLEDs and have the tendency for applications in other fields, such as sensing, bioimaging, and photocatalysis.

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In recent years, single-atom catalysts (SACs) have attracted enormous attention due their effectiveness in promoting a variety of catalytic reactions. However, the ability of SACs to enhance cancer phototherapies has received little attention to date. Herein, we synthesized a metal organic framework (MOF) rich in porphyrin-like single atom Fe­(III) centers (denoted herein as porphyrin-MOF or P-MOF) and then evaluated the performance of the P-MOF for cancer treatment by photodynamic therapy (PDT) and photothermal therapy (PTT) under NIR (808 nm) irradiation, as well as photoacoustic imaging (PAI) of tumors. On acccount of the abundance of single atom Fe­(III) centers, the P-MOF material demonstrated excellent performance for modulation of the hypoxic tumor microenvironment of Hela cell tumors in mice, while also demonstrating good properties as a photoacoustic imaging (PAI) agent. Density functional theory (DFT) calculations were used to elucidate the superior performance of P-MOF in these applications relative to Fe2O3 (a Fe­(III) reference compound). The calculations revealed that the narrow band gap energy of P-MOF (1.31 eV) enabled strong absorption of NIR photons, thereby inducing nonradiative transitions that converted incident light into heat to promote PTT. Further, a facile change of the spin state of the single atom Fe­(III) centers in P-MOF under NIR irradiation transformed coordinated triplet oxygen (3O2) to singlet oxygen (1O2), benefiting PDT. This work demonstrates the great future potential of both SACs and MOFs as multifunctional agents for cancer treatment and tumor imaging.

No abstract

In medical applications, two-dimensional nanomaterials have been widely studied on account of their intriguing properties such as good biocompatibility, stability, and multifunctionality. Herein, an ultrathin MnO2 nanosheet has been fabricated by a simplistic hydrothermal process. The high photothermal conversion performance (62.4%) can be attributed to the vacancy in the ultrathin MnO2 nanosheet, as confirmed by the extended X-ray absorption fine structure results and the density functional theory calculation, benefiting photoacoustic imaging-guided cancer therapy. This highly efficient vacancy-induced photothermal therapy has been reported for the first time. As a result, this work demonstrates that this ultrathin MnO2 nanosheet has a potential to construct a nanosystem for imaging-guided cancer therapy.

Currently, there is tremendous interest in the discovery of new and improved photothermal agents for near‐infrared (NIR)‐driven cancer therapy. Herein, a series of novel photothermal agents, comprising copper nanoparticles supported on defective porous carbon polyhedra are successfully prepared by heating a Cu‐BTC metal–organic framework (MOF) precursor at different temperatures (t) in the range 400–900 °C under an argon atmosphere. The copper nanoparticle size and carbon defect concentration in the obtained products (denoted herein as Cu@CPP‐t) increase with synthesis temperature, thus imparting the Cu@CPP‐t samples with distinct NIR absorption properties and photothermal heating responses. The Cu@CPP‐800 sample shows a remarkable photothermal conversion efficiency of 48.5% under 808 nm laser irradiation, representing one of the highest photothermal efficiencies yet reported for a carbon‐based photothermal agent. In vivo experiments conducted with tumor bearing nude Balb/c mice confirm the efficacy of Cu@CPP‐800 as a very promising NIR‐driven phototherapy agent for cancer treatment. Results encourage the wider use of MOFs as low cost precursors for the synthesis of carbon‐supported metal nanoparticle composites for photothermal therapy.

In this work, aminopropylmethylpolysiloxane (AMS) functionalized luminescent carbon dots (AMS-CDs) were prepared via a one-step solvothermal method. AMS-CDs could be self- or co-cross-linking with AMS to form 3D flexible transparent silicone rubbers (SRs) where CDs acted as cross-linking points, so the loading fraction of AMS-CDs could be adjusted from 10 to 100 wt %, thus modulating fluorescence properties and flexibility of silicone rubbers. Because of the self-curing property and high thermal stability, AMS-CDs were also studied in white LEDs (WLEDs), serving as a color conversion and encapsulation layer of GaN based blue LEDs simultaneously that would avoid the traditional problem of poor compatibility between emitting and packaging materials. And the color coordinate of AMS-CDs based WLEDs (0.33, 0.28) was very close to the pure white light. In addition, the obtained CDs cross-linked SRs had good transparency (T > 80%) at 510-1400 nm and high refractive indexes (1.33-1.54) that could meet the need of commercial packaging materials and optical application. AMS-CDs were also promising to be used in the UV LEDs based WLEDs according to their wide wavelength emission and flexible optoelectronic device.