Miruschenko, Mikhail Dmitrievich

Miruschenko M.D., Kosolapova K.D., Aleinik I.A., Borodina L.N., Vedernikova A.A., Sokolova A.V., Sandzhieva M.A., Mitroshin A.M., Yakimansky A.V., Koroleva A.V., Zhizhin E.V., Cherevkov S.A., Langer M., Otyepka M., Ushakova E.V., et. al.

Carbon dots (CDs) are fluorescent carbon nanomaterials that are considered for applications in optoelectronics, sensorics, and biofields due to their low‐cost and robust synthesis, and versatile optical properties. Herein, it is demonstrated how chemical functionalization of hydrophilic or amphiphilic CDs with polyethylene glycol influences their energy level structure and hence the emission properties. Functionalization of CDs with polyethylene glycol results in an increase in emission quantum yield: from 30% to 75% for hydrophilic CDs and from 20% to 25% for amphiphilic CDs. The estimated absolute values of energy levels, including the highest occupied molecular orbital and the lowest unoccupied molecular orbital energies, are dependent on chemical composition and size of CDs. Moreover, polyethylene glycol‐functionalized CD can form good quality films based on their composite with polyvinylcarbazole (PVK), that together with intense emission is crucial for light‐emitting diode (LED) fabrication. By studying spectral properties of fabricated CD‐LEDs, it is shown that their electroluminescence (EL) originates from mixed energy levels of CD and PVK in the composite, resulting in the shifting of the EL maximum from blue to green during several seconds of LED operation. The optimized CD‐LEDs show brightness up to 2600 cd m−2.

Efimova A.A., Badrieva Z.F., Brui E.A., Miruschenko M.D., Aleinik I.A., Mitroshin A.M., Volina O.V., Koroleva A.V., Zhizhin E.V., Liang Y., Qu S., Ushakova E.V., Stepanidenko E.A., Rogach A.L.

Karamysheva S.P., Cherevkov S.A., Miruschenko M.D., Aleinik I.A., Tatarinov D.A., Ushakova E.V.

Subject of study. The spectral features of nanocrystals with ternary compositions I-V-VI2 and I-III-VI2 doped with the rare earth metal ytterbium are investigated and described. Purpose of the study. The aim of this work is to develop a novel synthesis method for these nanocrystals to further examine their optical and morphological properties. Method. The average sizes of AgInS2:Yb and AgBiS2:Yb nanocrystals are analyzed using atomic force microscopy and dynamic light scattering, and the results are compared. Spectrophotometry and spectrofluorimetry are employed to record the absorption and photoluminescence spectra, respectively. Additionally, the photoluminescence decay kinetics are recorded using a laser scanning luminescence microscope for a deeper exploration of the electronic structure of the synthesized materials. Main results. Morphological analysis reveals that single-stage synthesis produced nanocrystals based on the AgInS2 matrix are smaller than the reference sample, while two-stage synthesis results in average nanocrystal sizes 1.5 times larger than the reference sample. The absorption spectra of the AgInS2:Yb and AgBiS2:Yb samples, as well as their reference samples, correspond to typical absorption spectra of semiconductor nanocrystals of ternary compounds. The absorption spectrum of AgBiS2:Yb nanocrystals, unlike AgInS2:Yb, spans a broad range from 300 nm to 1300 nm. In the photoluminescence spectra of AgInS2 and AgInS2:Yb nanocrystals, no significant shift of the band maximum is observed, and photoluminescence typical of Yb ions is absent. It is found that the weighted average photoluminescence lifetime in AgInS2:Yb nanocrystals can be modulated by ytterbium doping. Photoluminescence in AgBiS2 and AgBiS2:Yb samples is not detected in the red and near-infrared regions. Practical significance. These materials may be used in the fabrication of absorber layers for solar cells, as well as sensitizers for photodynamic and photothermal therapy. Further studies of isotropic samples of these nanocrystals could not only expand their potential applications but also enhance the physical properties of nanoparticles in the long term.

Efimova A.A., Badrieva Z.F., Brui E.A., Miruschenko M.D., Aleinik I.A., Mitroshin A.M., Volina O.V., Koroleva A.V., Zhizhin E.V., Stepanidenko E.A., Ushakova E.V.

Subject of study. This study is focused on luminescent carbon dots derived from o-phenylenediamine and gadolinium chloride or nitrate hexahydrate. Aim of study. The study aims to fabricate long-wavelength photoluminescent gadolinium-doped carbon dots that could function as contrast agents for magnetic resonance imaging. Additionally, the study investigates the impact of the precursor type used on the chemical composition and optical transitions of the resulting nanoparticles. Method. Carbon dots were synthesized using a one-step solvothermal method, and their composition and optical properties were analyzed using spectroscopy methods. Magnetic resonance imaging was conducted using a clinical magnetic resonance imaging scanner with a field strength of 1.5 T. Main results. In this study, two types of carbon dots were synthesized from o-phenylenediamine and gadolinium chloride or nitrate hexahydrate using the solvothermal method. Metal doping, at a concentration sufficient for further investigations, is achieved only when gadolinium chloride is used. Additionally, the presence of gadolinium chloride during the synthesis leads to the formation of luminescent centers within the carbon dots with emission at 600–720 nm and a photoluminescence quantum yield of 6.3%. In contrast, gadolinium nitrate increases the nitrogen content within the o-phenylenediamine-based carbon dots while inhibiting metal doping. The luminescent band with an emission maximum at 550 nm and a photoluminescence quantum yield of 7.4% originates from the o-phenylenediamine derivatives formed within such carbon dots. The study results also show that the gadolinium-doped carbon dots alter the relaxation times during magnetic resonance scanning, and the calculated relaxivity (r1 and r2) values are 6.4 and 38.6L⋅mmol−1⋅s−1, respectively. Thus, the synthesized carbon dots function as positive contrast agents during magnetic resonance scanning. Practical significance. Carbon dots with long-wavelength emission are promising nanoprobes for luminescence imaging. With gadolinium doping, these nanoparticles can also be used as contrast agents during magnetic resonance imaging. Consequently, carbon dots based on o-phenylenediamine and gadolinium chloride hexahydrate can be further utilized as dual-mode nanoprobes for bioimaging.

Stepanidenko E.A., Vedernikova A.A., Ondar S.O., Badrieva Z.F., Brui E.A., Miruschenko M.D., Volina O.V., Koroleva A.V., Zhizhin E.V., Ushakova E.V.

In this work, copper-doped carbon nanoparticles with emission in a wide spectral range and the ability to change the relaxation times of water protons during magnetic resonance imaging were fabricated. A high relaxivity value r1 = 0.92 mM–1 s–1 was achieved, which is the highest value of r1 for copper nanoparticles, to our knowledge. The suggested carbon nanoparticles are promising two-modal nanoprobes for bioimaging.

Cherevkov S.A., Stepanidenko E.A., Miruschenko M.D., Zverkov A.M., Mitroshin A.M., Margaryan I.V., Spiridonov I.G., Danilov D.V., Koroleva A.V., Zhizhin E.V., Baidakova M., Sokolov R.V., Sandzhieva M.A., Ushakova E.V., Rogach A.

The use of acetylacetone in combination with benzoic acid and ethylenediamine led to amphiphilic carbon dots formation with bright blue emission, which allowed us to produce LEDs, luminescent inks, and films for solar concentrators.

Vedernikova A.A., Miruschenko M.D., Arefina I.A., Xie J., Huang H., Koroleva A.V., Zhizhin E.V., Cherevkov S.A., Timin A.S., Mitusova K.A., Shipilovskikh S.A., Ushakova E.V.

Stepanidenko E.A., Vedernikova A.A., Miruschenko M.D., Dadadzhanov D.R., Feferman D., Zhang B., Qu S., Ushakova E.V.

Ушакова Е.В., Жижин Е.В., Королева А.В., Волина О.В., Мирущенко М.Д., Бруй Е.А., Бадриева З.Ф., Ондар С.О., Ведерникова А.А., Степаниденко Е.А.

In this work, copper-doped carbon nanoparticles with emission in a wide spectral range and the ability to change the relaxation times of water protons during magnetic resonance imaging were fabricated. A high relaxivity value r1 = 0.92 mM-1∙s-1 was achieved, which is the highest value of r1 for copper nanoparticles, to our knowledge. The suggested carbon nanoparticles are promising two-modal nanoprobes for bioimaging.

Cherevkov S., Stepanidenko E., Miruschenko M., Zverkov A., Margaryan I., Spiridonov I., Danilov D., Koroleva A., Zhizhin E., Baidakova M., Sokolov R., Sandzhieva M., Ushakova E., Rogach A.

On-going development of carbon dots (CDs) for different applications calls for search of novel methods for their synthesis and surface functionalization. For fabrication of light-emitting devices (LEDs), CDs should be soluble in non-polar solvents that are used for ink-printing of their functional layers, apart from the obvious requirement of bright luminescence. Herein, we introduce amphiphilic CDs synthesized from a mixture of benzoic acid and ethylenediamine in acetylacetone, which satisfy both above mentioned requirements. These CDs are quasi-spherical nanoparticles 20-50 nm in size, holding aliphatic, carbonyl, amide, imine, and carbamate groups at the surface which renders them amphiphilic and soluble in a variety of substances with relative polarity ranging from 0.002 to 1, such as toluene, chloroform, alcohols, and water. By variation of the molar ratio of benzoic acid and ethylenediamine, an optimal value for photoluminescence quantum yield of 36 % in non-polar solvents is achieved. Importantly, these CDs are easily mixable with a charge transport polymer – polyvinylcarbazole, a common component of organic LEDs. As a demonstration of use of developed amphiphilic CDs in LEDs, green emitting charge-injection devices are fabricated with a broad emission band centered at 515 nm, maximal luminance of 1716 cd/m2, and ССT of 5627 K.

Ondar S., Vedernikova A., Miruschenko M., Badrieva Z., Brui E., Stepanidenko E.

Stepanidenko E.A., Vedernikova A.A., Badrieva Z.F., Brui E.A., Ondar S.O., Miruschenko M.D., Volina O.V., Koroleva A.V., Zhizhin E.V., Ushakova E.V.

Luminescent carbon nanodots (CDs) are a low-toxic nanomaterial with a tunable emission in a wide spectral range and with various functional groups on the surface. Therefore, CDs can prospectively serve as luminescent nanoprobes for biomedical applications, such as drug-delivery, visualization, sensing, etc. The doping of CDs with paramagnetic or transition metals allows the expansion of the range of applications of CDs and the fabrication of a multimodal nanoprobe for bioimaging. Here, we developed CDs doped with manganese (Mn) based on commonly used precursors—o-phenylenediamine or citric acid and formamide. The chemical structure, morphology, optical properties, and magnetic resonance responses have been carefully studied. The obtained CDs are up to 10 nm, with emissions observed in the 400–650 nm spectral region. CDs exhibit an ability to reduce both T1 and T2 relaxation times by up to 6.4% and 42.3%, respectively. The high relaxivity values suggest the use of CDs as promising dual-mode contrast agents for T1 and T2 MRI. Therefore, our developed CDs can be utilized as a new multifunctional nanoscale probe for photoluminescent and magnetic resonance bioimaging.

Kosolapova K.D., Koroleva A.V., Arefina I.A., Miruschenko M.D., Cherevkov S.A., Spiridonov I.G., Zhizhin E.V., Ushakova E.V., Rogach A.

Chemically synthesized carbon dots (CDs) have attracted a lot of attention as an eco-friendly and cost-efficient light-emitting material, and functionalization of CD surface with additives of different nature is a...

Vedernikova A.A., Miruschenko M.D., Arefina I.A., Babaev A.A., Stepanidenko E.A., Cherevkov S.A., Spiridonov I.G., Danilov D.V., Koroleva A.V., Zhizhin E.V., Ushakova E.V.

Today, the development of nanomaterials with sensing properties attracts much scientific interest because of the demand for low-cost nontoxic colloidal nanoprobes with high sensitivity and selectivity for various biomedical and environment-related applications. Carbon dots (CDs) are promising candidates for these applications as they demonstrate unique optical properties with intense emissions, biocompatibility, and ease of fabrication. Herein, we developed synthesis protocols to obtain CDs based on o-phenylenediamine with a variety of optical responses depending on additional precursors and changes in the reaction media. The obtained CDs are N-doped (N,S-doped in case of thiourea addition) less than 10 nm spherical particles with emissions observed in the 300–600 nm spectral region depending on their chemical composition. These CDs may act simultaneously as absorptive/fluorescent sensing probes for solvent polarity with ∆S/∆ENT  up to 85, for ∆ENT from 0.099 to 1.0 and for pH values in the range of 3.0–8.0, thus opening an opportunity to check the pH in non-pure water or a mixture of solvents. Moreover, CDs preserve their optical properties when embedded in cellulose strips that can be used as sensing probes for fast and easy pH checks. We believe that the resulting dual-purpose sensing nano probes based on CDs will have high demand in various sensing applications.

Chen M., Ma J., Feng Y., Wu Y., Hu G., Liu X.

Roy B., Maikap A., Das S., Chakraborty S.

Yang B., Zhang Z., Luo Y., Li X., Chang H.

Fang Z., Li X., Zhang X., Yan W., Liu J., Zhao L.

Pei H., Zhang Z., Ouyang M., Liang H., Liu J., Li S., Zhang H., Qi Y., Wei L., Liu C., Shi L., Guo R., Liu N., Mo Z.

Li D., Wang X., Wang S., Song X., Fang L., Zhang Y., Ba X., Wang S.

Nikitin I.Y., Borodina L.N., Boltenko A.V., Baranov M.A., Gladskikh I.A., Vartanyan T.A.

Yaemsunthorn K., Sysło A., Krok-Janiszewska D., Kasprzyk W., Spilarewicz K., Pacia M., Thongpan W., Kobielusz M., Macyk W., Ortyl J.

Chen J., Li T., Lin C., Hou Y., Cheng S., Gao B.

Miruschenko M.D., Kosolapova K.D., Aleinik I.A., Borodina L.N., Vedernikova A.A., Sokolova A.V., Sandzhieva M.A., Mitroshin A.M., Yakimansky A.V., Koroleva A.V., Zhizhin E.V., Cherevkov S.A., Langer M., Otyepka M., Ushakova E.V., et. al.

Carbon dots (CDs) are fluorescent carbon nanomaterials that are considered for applications in optoelectronics, sensorics, and biofields due to their low‐cost and robust synthesis, and versatile optical properties. Herein, it is demonstrated how chemical functionalization of hydrophilic or amphiphilic CDs with polyethylene glycol influences their energy level structure and hence the emission properties. Functionalization of CDs with polyethylene glycol results in an increase in emission quantum yield: from 30% to 75% for hydrophilic CDs and from 20% to 25% for amphiphilic CDs. The estimated absolute values of energy levels, including the highest occupied molecular orbital and the lowest unoccupied molecular orbital energies, are dependent on chemical composition and size of CDs. Moreover, polyethylene glycol‐functionalized CD can form good quality films based on their composite with polyvinylcarbazole (PVK), that together with intense emission is crucial for light‐emitting diode (LED) fabrication. By studying spectral properties of fabricated CD‐LEDs, it is shown that their electroluminescence (EL) originates from mixed energy levels of CD and PVK in the composite, resulting in the shifting of the EL maximum from blue to green during several seconds of LED operation. The optimized CD‐LEDs show brightness up to 2600 cd m−2.

Nandi N., Sarkar P., Barnwal N., Sahu K.

AbstractDiscovered only in 2004, carbon dots (CDs) have already traversed a long journey, generating many promising research directions. Its cheapness, ease of synthesis, high water‐solubility, tunable emission, and excellent biocompatibility make it a single‐point solution to many problems, and tremendous efforts were invested into understanding the structure‐property‐function relationship, which eases the engineering of the CD properties suitable for a desired application. From the usual random choice of precursors or carbon materials as a starting point in the early days, more systematic approaches are now available for choosing proper starting materials and appropriate experimental conditions (solvent medium, reaction temperature, reaction duration, pH, etc) to customize its photoluminescence. The presence of impurities has a crucial role in the outcome and applicability of photoluminescence. Recently, a significant focus has been on the long‐wavelength emissive CDs, particularly in the red to near‐infrared (NIR) regions, for better penetration into live cells and to circumvent autofluorescence problems. Proper design can harvest phosphorescence from CDs. Many excellent reviews are available, focusing on different facets of CD prospects. Hence, we will only highlight the importance of the optical properties of CDs and ways to modulate them. We will mention some of the new works that have appeared in the last five years.

Pandey A., Raikwar V., Awade D.

Carbon dots (CDs) are extensively utilized in biomedicine, optical devices, and sensing due to their low toxicity, excellent optical properties, and ease of synthesis. Nonetheless, there is ongoing discussion over the comprehensive investigation of CDs photoluminescence (PL) process because of their intricate architectures and surface functions. Carbon dots (CDs) and CD/PVP composites were one step synthesized in a hydrothermal process using citric acid and NaOH as precursors. Due to surface defects of CDs after incorporating into Polyvinylpyrrolidone (PVP) both shift in color as well as change in emission is observed. It shows the enhancement of the luminescence property of CDs/PVP and the application of CD/PVP composite in the field of optical emission. Further for practical application, emission of white light emitting diodes (WLEDs) was demonstrated by coating a 370 nm UV-LED with CD/PVP composite. The WLED shows significant CRI, good S/P ratio, the color gamut score Rg and color fidelity score Rf which are essential features for a good light source. Our research offers a valuable reference for CD/PVP composites in a facile, low temperature and low-cost hydrothermal process and developing WLED with UV-LED and metal free phosphors.

Cai M., Lai L., Zhao M.

Efimova A.A., Badrieva Z.F., Brui E.A., Miruschenko M.D., Aleinik I.A., Mitroshin A.M., Volina O.V., Koroleva A.V., Zhizhin E.V., Liang Y., Qu S., Ushakova E.V., Stepanidenko E.A., Rogach A.L.

Mate N., Satwani V., Kumar P., Mobin S.M.

AbstractCarbon dots (CDs) are carbon‐based nanomaterials that have garnered immense attention owing to their exceptional photophysical and optoelectronic properties. They have been employed extensively for biomedical imaging and phototherapy due to their superb water dispersibility, low toxicity, outstanding biocompatibility, and exceptional tissue permeability. This review summarizes the structural classification of CDs, the classification of CDs according to precursor sources, and the luminescence mechanism of CDs. The modification in CDs via various doping routes is comprehensively reviewed, and the effect of such alterations on their photophysical properties, such as absorbance, photoluminescence (PL), and reactive oxygen species generation ability, is also highlighted. This review strives to summarize the role of CDs in cellular imaging and fluorescence lifetime imaging for cellular metabolism. Subsequently, recent advancements and the future potential of CDs as nanotheranostic agents have been discussed. Herein, we have discussed the role of CDs in photothermal, photodynamic, and synergistic therapy of anticancer, antiviral, and antibacterial applications. The overall summary of the review highlights the prospects of CD‐based research in bioimaging and biomedicine.

Zhang Y., Zhao H.

Carbon dots (CDs) offer tremendous advantages in the fields such as bioimaging, sensing, biomedicine, catalysis, information encryption, and optoelectronics. However, the inherent challenge is synthesizing CDs with a full-spectrum emission, as most CDs typically produce only blue or green emissions, which severely hinder further investigation into their fluorescence mechanism and restrict their broader applications in light-emitting diodes (LEDs). In this work, we reported a solvent-controlled strategy for the preparation of multicolor CDs with blue, yellow, and red emissions, using o-phenylenediamine (oPD) and ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6) as precursors. The detailed characterizations proved that a solvent with a lower boiling point and lower solubility of precursors resulted in a higher degree of dehydration and carbonization process, thereby increasing carbon cores with sp2-conjugated domains and nitrogen doping and further reducing the bandgap energies, causing a significant redshift emission from blue to red. The underlying fluorescence mechanism of the prepared multicolor CDs was contributed to the surface state. Eventually, blue-, yellow-, and red-emitting CDs based on poly(vinyl alcohol) (PVA) films and colorful LEDs devices were fabricated by dispersing the as-synthesized CDs into a PVA solution. The proposed solvent-controlled strategy for multicolor CDs preparation will be helpful for fully utilizing the advantages of CDs and expanding their applications.

Margaryan I.V., Vedernikova A.A., Borodina L., Kuzmenko N.K., Koroleva A.A., Zhizhin E.V., Zhang X., Ushakova E.V., Litvin A., Zheng W.

Abstract Solution-processed perovskite solar cells (PSCs) have demonstrated a tremendous growth in power conversion efficiency (PCE). A high-quality, defect-free perovskite-based active layer is a key point to enhance PSC performance. Introduction of additives and interlayers have proved to be an effective tool to passivate surface defects, control crystal growth, and improve PSC stability. Antisolvent engineering has emerged recently as a new approach, which aims to adjust perovskite layer properties and enhance the PCE and stability of PSC devices. Here, we demonstrate that carbon dots (CDs) may serve as a prospective additive for antisolvent engineering. Nitrogen-rich amphiphilic carbon dots were synthesized from amines by a solvothermal method and used as an additive to chlorobenzene for a perovskite layer fabrication. The interaction between perovskite and functional groups in CDs promotes improved crystallization of an active perovskite layer and defects passivation, bringing higher PSCs efficiency, stability, and suppressed hysteresis. Under optimized CD concentration, the maximum power conversion efficiency increased by 34 % due to the improved short-circuit current and fill factor, and the device maintains 87 % of its initial efficiency after 6 days of storage under ambient conditions.

Shu G., Jiang T., Zhang X., Zhao H.

Multimodal imaging is a potent technique that integrates complementary information from various imaging modalities, offering comprehensive insights into disease diagnosis. However, the development of biocompatible multimodal probes remains a challenge. In this study, we present the synthesis, characterization, and application of gadolinium and ytterbium co-doped carbon dots (Yb/Gd-CDs) for triple-modal fluorescence (FL)/magnetic resonance (MR)/computed tomography (CT) imaging. Notably, Yb and Gd were successfully incorporated into the lattice of CDs using a facile one‐pot hydrothermal approach to obtain Yb/Gd-CDs. The Yb/Gd-CDs demonstrated an ultra-small size, excellent colloidal stability, and low toxicity, making them suitable for further in vivo applications. Moreover, the Yb/Gd-CDs exhibited excellent fluorescence, high X-ray attenuation (40.17 HU/g/L), and high T1 relaxivity (11.16 mM-1s−1) with an ultra-low r2/r1 ratio of 1.08, showcasing remarkable performance in in vivo fluorescence, T1-weighted MR, and CT imaging of mice. Yb/Gd-CDs show great promise for in vivo multimodal imaging, and this work provides a highly biocompatible CDs-based theranostic platform with multiple functions for disease diagnosis.

Jin G., Cui Y., Wang T., Liu S., Xue S., Liu S., Ye Q., Zhou F., Liu W.

Arefina I.A., Erokhina D.V., Ushakova E.

Abstract In this work, composite materials were formed based on various matrices (polymer and porous cellulose matrix) and carbon dots (CDs) with intense room-temperature phosphorescence (RTP). The effect of post-synthesis chemical treatment with citric acid or urea on the optical properties of composites was studied: the increase in carboxy and carbonyl groups led to an increase of RTP signals that could be seen with the naked eye over several seconds. The fabricated composites demonstrated good stability and reversibility of RTP signals by mild heating. Based on the developed CDs, luminescent inks were used for a simple demonstration of the data encryption on paper.

Phukan P., Hatimuria M., Bag S., Pabbathi A., Das J.

Photoactive carbon dots (CDs) with emission in the spectral range of 600 nm to the near-infrared (NIR) region, referred to here as R/NIR CDs, are zero-dimensional nanomaterials that demonstrate good solubility in water, better photostability, and the ability to manipulate their surface. They offer superior biocompatibility for use in next-generation sensing, drug delivery, and treatment systems. Moreover, due to minimal photoluminescence (PL) interference from R/NIR CDs, along with deep tissue penetration ability and resistance to photon-induced damage, they have gained substantial popularity in challenging sectors such as tumor growth monitoring. This review captures the recent progress in this area, discussing important reports on bio and chemical sensing using R/NIR CDs, and intriguing in vivo bioimaging studies targeting tumor and cancer cells. Subsequently, the current progress in the field of phototherapy using these CDs is illustrated. We hope that this review will contribute to current advancements and assist researchers in inventing new CDs with improved properties for clinical applications.

Shi Y., Zhang Y., Wang Z., Yuan T., Meng T., Li Y., Li X., Yuan F., Tan Z., Fan L.

AbstractCarbon quantum dots are emerging as promising nanomaterials for next-generation displays. The elaborate structural design is crucial for achieving thermally activated delayed fluorescence, particularly for improving external quantum efficiency of electroluminescent light-emitting diodes. Here, we report the synthesis of onion-like multicolor thermally activated delayed fluorescence carbon quantum dots with quantum yields of 42.3–61.0%. Structural, spectroscopic characterization and computational studies reveal that onion-like structures assembled from monomer carbon quantum dots of different sizes account for the decreased singlet-triplet energy gap, thereby achieving efficient multicolor thermally activated delayed fluorescence. The devices exhibit maximum luminances of 3785–7550 cd m−2 and maximum external quantum efficiency of 6.0–9.9%. Importantly, owing to the weak van der Waals interactions and adequate solution processability, flexible devices with a maximum luminance of 2554 cd m−2 are realized. These findings facilitate the development of high-performance carbon quantum dots-based electroluminescent light-emitting diodes that are promising for practical applications.

Stepanidenko E.A., Vedernikova A.A., Ondar S.O., Badrieva Z.F., Brui E.A., Miruschenko M.D., Volina O.V., Koroleva A.V., Zhizhin E.V., Ushakova E.V.

In this work, copper-doped carbon nanoparticles with emission in a wide spectral range and the ability to change the relaxation times of water protons during magnetic resonance imaging were fabricated. A high relaxivity value r1 = 0.92 mM–1 s–1 was achieved, which is the highest value of r1 for copper nanoparticles, to our knowledge. The suggested carbon nanoparticles are promising two-modal nanoprobes for bioimaging.

Lü Z., Gao Q., Shi M., Su Z., Chen G., Qi H., Lü B., Peng F.

The preparation of mechanical robust organic room‐temperature phosphorescence (RTP) materials especially with white afterglow is attractive but rarely reported. Herein, a method to produce mechanical robust colorful RTP transparent wood (PTW) by infiltrating delignified wood with poly (vinyl alcohol) solutions containing arylboronic acids with various π conjugations is reported. The doubly rigid environment provided by the B─O covalent bonds and hydrogen bonds can stabilize the triplet excitons, leading to a ultralong lifetime of up to 2.13 s and excellent RTP emission stability (without obviously quenching over a month) of the target PTW. Besides, as a promising structural material for optical applications, the PTW shows combined advantages of multicolored persistent luminescence (from blue to green and then to red), good optical transmittance (≈90%), and striking mechanical strength (≈154 MPa). More importantly, by introducing appropriate amount of fluorescent dye rhodamine 6 G to the PTW with blue afterglow, white afterglow with a lifetime of 1.85 s is successfully achieve through triplet‐to‐singlet Förster resonance energy transfer. The PTW can function as afterglow window, anticounterfeiting label, and time delay lighting. This success paves the way for the development of mechanical robust, ecofriendly, and practical RTP materials.

Wang B., Wang H., Hu Y., Waterhouse G.I., Lu S.

Tuchin V.S., Stepanidenko E.A., Vedernikova A.A., Cherevkov S.A., Li D., Li L., Döring A., Otyepka M., Ushakova E.V., Rogach A.L.

AbstractFunctional nanostructures build up a basis for the future materials and devices, providing a wide variety of functionalities, a possibility of designing bio‐compatible nanoprobes, etc. However, development of new nanostructured materials via trial‐and‐error approach is obviously limited by laborious efforts on their syntheses, and the cost of materials and manpower. This is one of the reasons for an increasing interest in design and development of novel materials with required properties assisted by machine learning approaches. Here, the dataset on synthetic parameters and optical properties of one important class of light‐emitting nanomaterials – carbon dots are collected, processed, and analyzed with optical transitions in the red and near‐infrared spectral ranges. A model for prediction of spectral characteristics of these carbon dots based on multiple linear regression is established and verified by comparison of the predicted and experimentally observed optical properties of carbon dots synthesized in three different laboratories. Based on the analysis, the open‐source code is provided to be used by researchers for the prediction of optical properties of carbon dots and their synthetic procedures.

Cherevkov S.A., Stepanidenko E.A., Miruschenko M.D., Zverkov A.M., Mitroshin A.M., Margaryan I.V., Spiridonov I.G., Danilov D.V., Koroleva A.V., Zhizhin E.V., Baidakova M., Sokolov R.V., Sandzhieva M.A., Ushakova E.V., Rogach A.

The use of acetylacetone in combination with benzoic acid and ethylenediamine led to amphiphilic carbon dots formation with bright blue emission, which allowed us to produce LEDs, luminescent inks, and films for solar concentrators.

Chen X., Han X., Zhang C., Ou X., Liu X., Zhang J., Liu W., Ragauskas A.J., Song X., Zhang Z.

Light‐emitting diodes (LEDs) are widely used in lighting and display applications. Carbon quantum dots (CQDs), which have high biocompatibility, high resistance to photobleaching, and full‐spectrum luminescence, have inherent advantages as fluorescent materials for LED devices. Herein, multicolor CQDs are prepared by a new reagent engineering strategy due to the difference of effective conjugate length and the surface electron‐withdrawing groups of CQDs. White CQDs are realized by mixing blue, green, and red CQDs proportionally. Then, the aggregation‐caused quenching phenomenon of CQDs is suppressed through the hydrogen‐bonding network of cellulose nanofibrils (CNFs). Multicolor fluorescent films are prepared from CQDs and CNFs by simple mixing and casting methods. Finally, thin‐film encapsulation based on the photosensitive resin ABPE‐10 coating can be realized and rapidly assembles into fluorescent films with different light‐emitting colors into LED devices, leading to have superior thermal performance compared with conventional LEDs. White LEDs have excellent white‐light illumination performance, with Commission Internationale de L’Eclairage color coordinates of (0.33, 0.37), a correlated color temperature of 5688 K, and a color rendering index of 86. This strategy provides a convenient and scalable pathway for low‐cost, environmentally friendly, and high‐performance CQDs‐based LEDs.

Wang J., Shi Y., Mao B., Zhang B., Yang J., Hu Z., Liao W.

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disease characterized by intestinal tract inflammation. Although the incidence of IBD is increasing globally, the mechanisms underlying its pathogenesis remain unclear. Numerous drugs have been recently used to treat the disease; however, they have several shortcomings, such as poor stability, poor solubility, and low biosafety. In recent years, research on biomaterials to address the challenges encountered in IBD treatment has increased and is extensive. Different types of biomaterials play different roles in IBD due to their unique characteristics, and different types of macromolecular preparations are applied according to their physical and chemical properties. In addition, biomaterial-based drug delivery systems are expected to overcome the limitations of traditional oral drug delivery, and offer novel opportunities for IBD treatment via oral drug administration. Intestinal organoids have also become a research hotspot in recent years in IBD studies, with key roles in IBD pathogenesis, drug screening. The present article reviews research and the roles of various biomaterials in IBD treatment to enhance our understanding of research trends in biomaterials in IBD in recent years and facilitate IBD treatment and further research.

Wang F., Dong X., Zuo Y., Xie Z., Guan R.

Red-emitting carbon dots have attracted much attention because of their excellent fluorescence properties. It is of great significance to synthesize red-emitting carbon dots with high fluorescence quantum yield. Herein, by using citric acid and 1,8-diaminonaphthalene as precursors in N, N-dimethylformamide, novel carbon dots (NC-CDs) exhibiting red emission at 607 nm upon excitation at 514 nm were synthesized via a solvent-thermal approach. NC-CDs aggregated in lipid droplets of cells, and hemin quenched their fluorescence. Subsequently, cationic surfactants cetyltrimethylammonium bromide, anionic surfactants sodium dodecyl sulfate and nonionic surfactants were used to functionalize the NC-CDs. The results indicated that both ionic surfactants increased the fluorescence quantum yield and solubility of NC-CDs with extended fluorescence lifetime. This approach is applicable to a class of carbon dots that possess both carboxyl and amino groups. Additionally, these functionalized NC-CDs exhibited high recognition sensitivity towards ClO− and Cu2+ respectively except for hemin. This study provides a novel approach for the synthesis of highly red-emitting carbon dots, expanding their applications in the field of biological imaging and sensing. The findings hold significant implications for the real-time monitoring of hemin in lipid droplets. Additionally, this work offers a simple method to dramatic enhance their fluorescence quantum yield.