Copper and cobalt co-doped ZnS (ZnS:Cu,Co) afterglow nanoparticles were conjugated to photosensitizer tetrabromorhodamine-123 (TBrRh123) and efficient energy transfer from the nanoparticles to TBrRh123 was observed. In addition to their X-ray excited luminescence, the ZnS:Cu,Co nanoparticles also show long lasting afterglow, which continuously serve as a light source for photodynamic therapy (PDT) activation. Compared to TBrRh123 or ZnS:Cu,Co alone, the ZnS:Cu,Co-TBrRh123 conjugates show low dark toxicity but high X-ray induced toxicity to human prostate cancer cells. The results indicate that the ZnS:Cu,Co afterglow nanoparticles have a good potential for PDT activation.

Iodine ion is one of the most indispensable anions in living organisms, particularly being an important substance for the synthesis of thyroid hormones. Curcumin is a yellow-orange polyphenol compound derived from the rhizome of Curcuma longa L. , which has been commonly used as a spice and natural coloring agent, food additives, cosmetics as well as Chinese medicine. However, excess curcumin may cause DNA inactivation, lead to a decrease in intracellular ATP levels, and trigger the tissue necrosis. Therefore, quantitative detection of iodine and curcumin is of great significance in the fields of food and life sciences. Herein, we develop nitrogen-doped fluorescent carbon dots (NCDs) as a multi-mechanism detection for iodide and curcumin in actual complex biological and food samples, which was prepared by a one-step solid-phase synthesis using tartaric acid and urea as precursors without adding any other reagents. An assembled NCDs-Hg 2+ fluorescence-enhanced sensor for the quantitative detection of I − was established based on a fluorescence “turn-off-on” mechanism in a linear range of 0.3–15 μM with a detection limit of 69.4 nM and successfully quantified trace amounts of I − in water samples and urine sample. Meanwhile, the as-synthesized NCDs also can be used as a fluorescent quenched sensor for curcumin detection based on the synergistic internal filtration effect (IFE) and static quenching, achieving a good linear range of 0.1–20 μM with a satisfactory detection limit of 29.8 nM. These results indicate that carbon dots are potential sensing materials for iodine and curcumin detection for the good of our health.

Aggregation-induced emission luminogens (AIEgens) exhibit efficient cytotoxic reactive oxygen species (ROS) generation capability and unique light-up features in the aggregated state, which have been well explored in image-guided photodynamic therapy (PDT). However, the limited penetration depth of light in tissue severely hinders AIEgens as a candidate for primary or adjunctive therapy for clinical applications. Coincidentally, microwaves (MWs) show a distinct advantage for deeper penetration depth in tissues than light. Herein, for the first time, we report AIEgen-mediated microwave dynamic therapy (MWDT) for cancer treatment. We found that two AIEgens ( TPEPy-I and TPEPy-PF6 ) served as a new type of microwave (MW) sensitizers to produce ROS, including singlet oxygen ( 1 O 2 ), resulting in efficient destructions of cancer cells. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and live/dead assays reveal that the two AIEgens when activated by MW irradiation can effectively kill cancer cells with average IC-50 values of 2.73 and 3.22 μM, respectively. Overall, the ability of the two AIEgens to be activated by MW not only overcomes the limitations of conventional PDT, but also helps to improve existing MW ablation therapy by reducing the MW dose required to achieve the same therapeutic outcome, thus reducing the occurrence of side-effects of MW radiation.

Carbon nanodots are nanometer sized fluorescent particles studied for their distinct photoluminescent properties and biocompatibility. Although extensive literature reports the modification and application of carbon nanodot fluorescence, little has been published pertaining to phosphorescence emission from carbon nanodots. The use of phosphors in biological imaging can lead to clearer detection, as the long lifetimes of phosphorescent emission permit off-gated collection that avoids noise from biological autofluorescence. Carbon nanodots present a desirable scaffold for this application, with advantageous qualities ranging from photostability to multi-color emission. This research reports the generation of a novel phosphorescent "heavy carbon" nanodot via halogenation of the carbon nanodot structure. By employing a collection pathway that effectively incorporates bromine into the nanostructure, T1 triplet character is introduced, and subsequently phosphorescence is observed in liquid media at room temperature for the first time in the nanodot literature. Further experiments are reported characterizing the conditions of observed phosphorescence and its pH-dependence. Our approach for producing "heavy carbon nanodots" is a low-cost and relatively simple method for generating the phosphorescent nanodots, which sets the foundation for its potential future use as a phosphorescent probe in application.