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Abstract: Luminescent carbon nanoparticles (CNPs) had shown great impact on bioimaging and environmental applications recently. Here an inexpensive but practical solovethermal method is developed to prepare CNPs using tartaric acid and ammoniumoxalate as starting materials in one-pot. This approach allows large-scale production of aqueous CNPs dispersions without any post-treatment process. The product CNPs have amorphous structures, with diameter of about 10–30nm, exhibit an excitation-independent photoluminescence (PL) behavior. Meanwhile, CNPs showed UV-light sensitive photocatalytic activity for methylene blue (MB) degradation, indicating CNPs potential applications in environment or energy areas. [Copyright &y& Elsevier]

Abstract: A new type of self-assembled film was prepared by alternating deposition of oppositely charged meso-tetra-(4-trimethylaminophenyl) porphyrin nickel iodide (NiTAPPI) and citrate-stabilized CdSe nanoparticles. The stepwise deposition process was monitored by means of UV–vis spectroscopy. The interaction between the porphyrin and CdSe nanoparticles was characterized with UV–vis and fluorescence spectra. The SEM images showed the formation of densely packed two-dimensional array and the conversion of disorder-to-order of CdSe nanoparticles on the quartz substrate modified by PDDA when depositing positively charged NiTAPPI. The self-assembled film placed in ambient air exhibited significant enhancement of fluorescence intensity. The effects of heat treatment and UV-light irradiating on fluorescence properties of the composite films were investigated in details. [Copyright &y& Elsevier]

Although neutral luminescent radicals have arisen much attention recently, their applications in fluorescence imaging are rarely reported due to their insolubility in water and weak luminescence in polar solvents. Herein, we encapsulated a luminescent radical and its precursor into nanoparticles (NPs) by an amphiphilic polymer matrix, DSPE-PEG 2000 , to avoid aggregation-caused quenching and poor solubility in water to further achieve its application in cell-imaging. The obtained radical NPs exhibited strong red emission, excellent stability and remarkable biocompatibility under physiological conditions. The radical NPs were incubated with live HCT116 cells and showed good cellular uptake, thus making fluorescence imaging possible in vitro. The results confirm the feasibility of stable neutral luminescent radical as a promising candidate for the application in fluorescence imaging. [Display omitted] • Radical nanoparticles consist of the luminescent radical and its precursor were encapsulated together within an amphiphilic polymer matrix at an optimized proportion. • Radical nanoparticles exhibited bright red emission and excellent biocompatibility. • Radical nanoparticles can be internalized into HCT116 cells and become a promising tool in fluorescence imaging. [ABSTRACT FROM AUTHOR]

FeO/CNTs nanocomposites, which were prepared by polyol-medium in situ high-temperature decomposition of Fe( acac) using PVP as stabilizing agent and modified with SDS, were further decorated with high-quality ZnS nanocrystal via a wet technique in glycol solution. The obtained ZnS/FeO/CNTs nanohybrids were characterized by XRD, FT-IR, Raman microscope, TEM, EDS, XPS, VSM and fluorophotometers. Results indicated that magnetic FeO nanoparticles and fluorescent ZnS nanocrystal were uniformly dispersed on the surface of CNTs layer-by-layer with PVP and SDS as stabilizing agent and ion-capture agent, respectively. The novel multi-functional nanohybrids exhibit super-paramagnetic properties with a saturation magnetization about 6·795 emu g at room temperature and show a strong emission band at 367 nm with a broad shoulder around 342-483 nm due to the interactions and/or background emissions of FeO and CNTs. The superparamagnetic and fluorescent properties of obtained products are promising for potential applications in magnetically guided and fluorescence tracing drug delivery systems. [ABSTRACT FROM AUTHOR]

Abstract: Up-conversion nanoparticles (UCNPs), which can convert a longer wavelength radiation to a shorter wavelength radiation, have great potential use as bio-labels in biological detection. However, these NPs usually cannot be used directly unless their surface is further modified. Herein, we developed a novel and straightforward method for the synthesis of monodisperse NaYF4:Yb,Er/Polymer UCNPs. The resultant UCNPs exhibited a pure hexagonal phase, strong UC fluorescent intensity, and a uniform size of about 40nm, which were characterized by XRD, luminescence spectroscopy and TEM, respectively. FT-IR spectra revealed that these NPs were coated with a layer of hydrophilic polymers (including PVP, PEG, PAA and PEI), thus the NPs could be dispersed in water easily. More importantly, the PAA and PEI coated NPs were functionalized by –COOH and –NH2 groups, respectively, which were expected to be used for further bio-conjugation. [Copyright &y& Elsevier]