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Triplet excitons usually do not emit light under ambient conditions due to the spin-forbidden transition rule, thus they are called dark excitons. Herein, triplet excitons in carbon nanodots (CNDs) are brightened by embedding the CNDs into poly(vinyl alcohol) (PVA) films; flexible multicolor phosphorescence films are thus demonstrated. PVA chains can isolate the CNDs, and excited state electron or energy transfer induced triplet exciton quenching is thus reduced; while the formed hydrogen bonds between the CNDs and PVA can restrict vibration/rotation of the CNDs, thus further protecting the triplet excitons from nonradiative recombination. The lifetimes of the flexible multicolor phosphorescence films can reach 567, 1387, 726, and 311 ms, and the longest-lasting phosphorescence film can be observed by naked eyes for nearly 15 s even after bending 5000 times. The phosphorescence films can be processed into various patterns, and a dynamic optical signature concept has been proposed and demonstrated based on the phosphorescence films.

Phosphorescent carbon nanodots (CNDs) have various attractive properties and potential applications, but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods. Herein, a large-scale synthesis method for phosphorescent CNDs has been demonstrated via precursors’ self-exothermic reaction at room temperature. The as-prepared CNDs show fluorescence and phosphorescence property, which are comparable with that synthesized by solvothermal and microwave method. Experimental and computational studies indicate that exotic atom doped sp2 hybridized carbon core works as an emissive center, which facilities the intersystem crossing from singlet state to triplet state. The CNDs show phosphorescence with tunable lifetimes from 193 ms to 1.13 s at different temperatures. The demonstration of large-scale synthesis of phosphorescent CNDs at room temperature opens up a new window for room temperature fabrication phosphorescent CNDs.

Water-soluble red afterglow imaging agents based on ecofriendly nanomaterials have potential application in time-gated afterglow bioimaging due to their larger penetration depth and nondurable excitation. Herein, red afterglow imaging agents consisted of Rhodamine B (RhB) and carbon nanodots (CNDs) have been designed and demonstrated. In these agents, CNDs act as energy donors, and RhB acts as an energy acceptor. Both of them are confined into a hydrophilic silica shell to form a CNDs-RhB@silica nanocomposite. The phosphorescence emission spectrum of the CNDs and the absorption spectrum of the RhB match well, and efficient energy transfer from the CNDs to the RhB via Forster resonant energy transfer process can be achieved, with a transfer efficiency can reach 99.2%. Thus, the as-prepared nanocomposite can emit a red afterglow in aqueous solution, and the afterglow spectrum of CNDs-RhB@silica nanocomposite can extend to the first near-infrared window (NIR-I). The luminescence lifetime and afterglow quantum yield (QY) of the CNDs-RhB@silica can reach 0.91 s and 3.56%, respectively, which are the best results in red afterglow region. Time-gated in vivo afterglow imaging has been demonstrated by using the CNDs-RhB@silica as afterglow agents.

Two tandem column fixed, respectively, with tetraethylenepentamine modified bagasse (AM-BS) and phosphoric acid modified bagasse (PA-BS) were prepared and used to simultaneously recycle Cu2+ and Pb2+ from metallurgical wastewater containing Cu2+, Pb2+, Cd2+, Zn2+, Ca2+ and Mg2+. For comparison, removal of Cu2+ and Pb2+ by single column fixed either with AM-BS or PA-BS was also carried out in unitary and wastewater system. Results in single column experiments showed that AM-BS column showed high adsorption affinity toward Cu2+ while PA-BS showed high affinity toward Pb2+. AM-BS could selectively remove Cu2+ while PA-BS could selectively remove Pb2+ from aqueous solution. Adsorption mechanism verified by EDX illustrated that Cu2+ and Pb2+ was selectively adsorbed through competitive substitution reaction, where metal ions with higher affinity substituted the others with lower affinity during sorption process. Two tandem column experiments showed that amount of Cu2+, Pb2+, Cd2+, Zn2+, Ca2+ and Mg2+ adsorbed on AM-BS was 0.17, 0.003, 0.001, 0.006, 0.013 and 0.009 mmol g−1 and that on PA-BS was 0.04, 0.24, 0.002, 0.018, 0.028 and 0.005 mmol g−1, respectively, demonstrating that Cu2+ and Pb2+ were simultaneously removed from wastewater. Tandem columns fixed with different modified biosorbent had great potential in multi-metal recovery.

Red/near‐infrared (NIR) emissive carbon nanodots (CNDs) with photoluminescence (PL) quantum yield (QY) of 57% are prepared via an in situ solvent‐free carbonization strategy for the first time. 1‐Photon and 2‐photon cellular imaging is demonstrated by using the CNDs as red/NIR fluorescence agent due to the high PL QY and low biotoxicity. Further study shows that the red/NIR CNDs exhibit multiphoton excited (MPE) upconversion fluorescence under excitation of 800–2000 nm, which involves three NIR windows (NIR‐I, 650–950 nm; NIR‐II, 1100–1350; NIR‐III, 1600–1870 nm). 2‐Photon, 3‐photon, and 4‐photon excited fluorescence of the CNDs under excitation of different wavelengths is achieved. This study develops an in situ solvent‐free carbonization method for efficient red/NIR emissive CNDs with MPE upconversion fluorescence, which may push forward the application of the CNDs in bioimaging.

Deep-ultraviolet (DUV) emissive carbon nanodots (CNDs) have been designed theoretically and demonstrated experimentally based on the results of first-principles calculations using the density functional theory method. The emission of the CNDs is located in the range from 280 to 300 nm, which coincides well with the results of theoretical calculation results. The photoluminescence (PL) quantum yield (QY) of the CNDs is up to 31.6%, and the strong emission of the CNDs originates from core-state (π-π*) carriers' radiative recombination and surface passivation. Benefiting from the core-state emission and surface group passivation, the emission of the CNDs is independent of the excitation wavelength and ambient solvent. DUV light-emitting diodes (LEDs) have been fabricated based on the DUV emissive CNDs, and the LEDs can be used as the excitation source to excite blue, green, and red CNDs, indicating their potential application in DUV light sources. This work may provide a clue for the designing and realizing of DUV emissive CNDs, thus promising the potential application of CNDs in DUV light-emitting sources.

Poor stability as an essential issue of metal halide perovskites (MHPs), limits their further applications in displaying and lighting. Among multicolor luminous MHPs, the development of blue luminous perovskite lags far behind that of red and green emission. Herein, a “MAPbBrxCl3-x quantum dots (QDs) in Pb(OH)Br” strategy is proposed, fabricating stable MAPbBrxCl3-x@Pb(OH)Br with the emission wavelength of 435–485 nm. Experimental characterizations indicate that cubic MAPbBrxCl3-x transforms into rectangular MAPbBrxCl3-x@Pb(OH)Br with the assistance of methylamine vapor. The as-prepared MAPbBrxCl3-x@Pb(OH)Br shows high stability of water, light, heat and organic solvents, which can emit bright emission even they are immersed in water for 6 months. In addition, anion exchange induced spectral shift of the MHPs are also suppressed due to the chemical inertness of Pb(OH)Br. Notably, this strategy is also applied to all inorganic halide perovskites. Blue light-emitting devices (LEDs) based on the MAPbBrxCl3-x@Pb(OH)Br have been demonstrated, which can run stably for over 8 h with brightness exceeding 1000 cd/m2 in a humid environment.

Photodynamic therapy employs photosensitive agents such as porphyrins to treat a variety of tumors accessible to light-emitting probes. This approach capitalizes on the selective retention of porphyrins by cancer cells. Cancer cells also have elevated levels of mitochondrial benzodiazepine receptors which bind porphyrins with high affinity. Cultured cancer cell lines were exposed to porphyrin and porphyrin-like compounds and then irradiated with light. Cytotoxicity of this treatment was measured via clonogenic assays. Mitochondrial benzodiazepine receptor pharmacology was studied using [3H] PK11195 binding to cancer cell homogenates and isolated kidney mitochondrial membranes. We show that therapeutic potencies of porphyrins correlate closely with affinities for mitochondrial benzodiazepine receptors. Sensitivities of tumor cell lines to photodynamic therapy parallel their densities of these receptors. We propose that porphyrin photodynamic therapy is mediated by mitochondrial benzodiazepine receptors.

Purpose: To identify those factors that predict variability in tumor response to 90 Y-radioimmunotherapy based on measurement of incorporated activity and physical dimensions of individual tumors and to apply the concept of effective dose to radioimmunotherapy. Methods and Materials: Human colon carcinoma xenografts growing in nude mice were treated with anti-CEA antibodies labeled with 90 Y directly or through a bispecific antibody/labeled hapten system. Tumor response was measured as the delay in growth to eight times the treatment volume. Noninvasive activity (based on bremsstrahlung radiation) and dimension measurements were made in these animals at several times after label injection. The following parameters were compared for their ability to predict individual tumor response: (a) injected activity, (b) injected activity times a factor based on average uptake as a function of voluem, (c) in vivo activity per volume measured in each animal at a single time, 9d) the integral over time of in vivo activity per volume in each animal, and (e) the minimum dose for each animal in a uniformly active ellipsoid whose total activity and dimensions varied over time the same as the tumor. Results and Conclusion: After correcting for differences in injected activity, two parameters account for much of the variability in tumor response. One of these is the general trend of larger tumors to take up less activity per volume. Additional variability can be accounted for by the vivo activity per volume measurements. The minimum dose as introduce here is likely to be useful in estimating the biologically effective dose delivered by each treatment.