Starch-regulated copper-terephthalic acid as a pH/hydrogen peroxide simultaneous-responsive fluorescent probe for lysosome imaging.

Lysosome visualization is very important for accurate diagnosis of human diseases. However, currently developed lysosome imaging probes usually have poor specificity and are easily quenched, leading to a low signal to noise ratio in lysosome labeling. To resolve this problem, herein, metal-organic framework-based probes of copper-terephthalic acid (CuBDC) are investigated, which show sensitivity to pH and hydrogen peroxide (H2O2), simultaneously. By self-assembling under the template effect of soluble starch, the particle size of CuBDC can be well controlled for entering into cells and locating lysosomes. Based on the Fenton-like reaction, CuBDC can catalyze the decomposition of H2O2 into ˙OH, which in turn reacts with CuBDC to generate a stable fluorescent substance. Meanwhile, Cu2+ can be released from CuBDC under acidic conditions for reacting with H2O2 more thoroughly. And the synthesized CuBDC has a similar attraction to the electrophilic ˙OH at different pH values owing to the residual soluble starch in the particles. The above properties cause CuBDC to have a stable fluorescence signal with low pH values and high H2O2 concentration, simultaneously. The fluorescence imaging experiments in HeLa cells demonstrate that CuBDC acting as a pH/H2O2 responsive fluorescent probe holds great promise for lysosome-specific imaging.

Biowaste-derived 3D honeycomb-like N and S dual-doped hierarchically porous carbons for high-efficient CO2 capture.

Considering the characteristics of abundant narrow micropores of <1 nm, appropriate proportion of mesopores/macropores and suitable surface functionalization for a highly-efficient carbon-based CO2 adsorbent, we proposed a facile and cost-effective strategy to prepare N and S dual-doped carbons with well-interconnected hierarchical pores. Benefiting from the unique structural features, the resultant optimal material showed a prominent CO2 uptake of up to 7.76 and 5.19 mmol g-1 at 273 and 298 K under 1 bar, and importantly, a superb CO2 uptake of 1.51 mmol g-1 at 298 K and 0.15 bar was achieved, which was greatly significant for CO2 capture from the post-combustion flue gases in practical application. A systematic study demonstrated that the synergetic effect of ultramicroporosity and surface functionalization determined the CO2 capture properties of porous carbons, and the synergistic influence mechanism of nitrogen/sulfur dual-doping on CO2 capture performance was also investigated in detail. Importantly, such as-prepared carbon-based CO2 adsorbents also showed an outstanding recyclability and CO2/N2 selectivity. In view of cost-effective fabrication, the excellent adsorption capacity, high selectivity and simple regeneration, our developed strategy was valid and convenient to design a novel and highly-efficient carbonaceous adsorbent for large-scale CO2 capture and separation from post-combustion flue gases.

[Determination of pazufloxacin mesylas by terbium sensitized chemiluminescence method].

Tb3+ can form chelate with pazufloxacin mesylas (PM), and the complex of terbium-pazufloxacin mesylas(Tb3+-PM) can sensitize the chemiluminescence (CL) intensity of KMnO4-Na2SO3 system through energy transfer. Based on the chemiluminescence reaction, a new sensitized chemiluminescence method was developed for the determination of PM by flow-injection. Under the optimum conditions, the enhanced CL intensity was linear with the concentration of PM in the range of 0.10-12 mg x L(-1) with the detection limit of 0.04 mg x L(-1). The relative standard deviation for eleven continuous determinations of 1.0 mg x L(-1) PM was 1.9%. This method has been applied to the determination of PM in injection and body fluid with satisfactory results. This method has the merits of simpleness, speediness, sensitivity and good reproducibility. An original mechanism was proposed to explain this phenomenon.

[Preliminary investigation on endocrine disrupting chemicals in a sewage treatment plant of Beijing].

Endocrine disrupting chemicals (EDCs) existed in the water treatment units of Beijing based Sewage Treatment Plant were analyzed by SPE-GC/MSD and GC/ECD. Totally 30 EDCs were detected from the influent, effluent and sludge. The results show that about 70%-99% EDCs in the influent were removed after treatment. Sludge adsorption played an important role in the reduction of EDCs. The range of phenols in sludge was 17-35 mg/kg, the range of PAEs was 25-77 mg/kg and the range of PAHs was 1.33-1.74 mg/kg. Compared with the results in other countries in literature, the existence of EDCs in the Sewage Treatment Plant was not serious.