Detection of sulphur(II) of carbon dots synthesized from Gardenia residue.

The detection of anions using carbon dots (CDs) has received less attention compared to cations. Therefore, the present study aimed to develop a fluorescence sensor based on carbon dots (CDs) capable of detecting S2- in real water samples. The CDs were successfully prepared from the residues of a traditional Chinese herb, Gardenia, which emitted green photoluminescence (PL) under ultraviolet light irradiation. The as-prepared CDs were quasi-spherical in shape and ranged in size from 10 to 30 nm. Different detailed analyses proved that the CDs had good morphology, various functional groups, high water solubility, great optical features, and excellent stability under diverse environmental conditions. The ion detection showed that only Ag+ had the strongest fluorescence quenching effect on the CDs, however, the addition of S2- could recover their fluorescence. Based on these results, an "off-on" fluorescence sensor was achieved to selectively detect the concentration of S2- in real water samples with a limit of detection (LOD) of 39 µM, which further expanded the application of residues from traditional Chinese herbal medicine.

Design, synthesis and inhibitory activity against Candida albicans of a series of derivatives with 5-nitrofuran scaffold.

The increasing resistance of Candida albicans against the currently available antifungal drugs has exerted enormous damage to human health. To develop novel and efficient antifungal agents with unique structure, a series of derivatives containing 5-nitrofuran scaffold (33 examples) were designed, synthesized, and screened the in vitro antifungal activities. Bioassay results disclosed that 5-nitrofuran derivatives could dramatically inhibit the growth of six strains of Candida albicans, particularly the drug-resistant clinical ones. There were ten kinds of compounds exhibited stronger inhibitory activities against tested fungi than those of fluconazole. For all tested fungi, B5 showed the highest activity with the MIC80 values of 0.25-8 µg/mL. The results of cytotoxicity assay displayed that B5 hardly influenced the growth of HL-7702 cell lines, consequently, it was safe for people and animals. The preliminary exploration of antifungal mechanism documented that B5 could destroy the morphology of tested fungi, facilitate the formation of reactive oxygen species, ultimately inhibited the proliferation of the tested fungi. In conclusion, a new and safe lead compound was successfully developed for the treatment of Candida albicans infection.