The photoluminescence of carbon nanodots (C‐dots) can be tuned by changing their surface chemistry or size because the photoluminescence is a function of the surface‐state electronic transitions. ...Increasing the degree of surface oxidation leads to a narrowing of the energy gap of the surface; meanwhile, larger C‐dots with an extensive π‐electron system, which can couple with surface electronic states, can also lead to a narrowing of the energy gap of the surface states.
The size of C‐nanodots can be electrochemically tuned by changing the applied potential during their preparation. The higher the applied potential, the smaller the resulting C‐nanodots. Moreover, the ...surface oxidation degree of the C‐nanodots can also be electrochemically tuned. The red‐shift of emission independent of the size provides an insight into the luminescence mechanism of C‐nanodots.
Mechanofluorochromic materials, which change their photoluminescence (PL) colors in responding to mechanical stimuli, can be used as mechanosensors, security papers, and photoelectronic devices. ...However, traditional mechanofluorochromic materials can only be adjusted to a monotone direction upon the external stimuli. Controllable pressure‐triggered blue‐ and red‐shifted PL is reported for C‐dots. The origin of mechanofluorochromism (MFC) in C‐dots is interpreted based on structure–property relationships. The carbonyl group and the π‐conjugated system play key roles in the PL change of C‐dots under high pressure. As the pressure increases, the enhanced π–π stacking of the π‐conjugated system causes the red‐shift of PL, while the conversion of carbonyl groups eventually induces a blue‐shift. Together with their low toxicity, good hydrophilicity, and small size, the tunable MFC property would boost various potential applications of C‐dots.
Bidirectional mechanofluorochromic C‐dots with a controllable blue‐or red‐shift of photoluminescence (PL) spectra was achieved under high pressure by adjusting their relative contents of carbonyl groups and a π‐conjugated system. The origin of mechanofluorochromism in C‐dots is interpreted using structure–property relationships.
Ag2S quantum dots (QDs) are well‐known near‐infrared fluorophores and have attracted great interest in biomedical labeling and imaging in the past years. However, their photoluminescence efficiency ...is hard to compete with Cd‐, Pb‐based QDs. The high Ag+ mobility in Ag2S crystal, which causes plenty of cation deficiency and crystal defects, may be responsible mainly for the low photoluminescence quantum yield (PLQY) of Ag2S QDs. Herein, a cation‐doping strategy is presented via introducing a certain dosage of transition metal Pb2+ ions into Ag2S nanocrystals to mitigate this intrinsic shortcoming. The Pb‐doped Ag2S QDs (designated as Pb:Ag2S QDs) present a renovated crystal structure and significantly enhanced optical performance. Moreover, by simply adjusting the levels of Pb doping in the doped nanocrystals, Pb:Ag2S QDs with bright emission (PLQY up to 30.2%) from 975 to 1242 nm can be prepared without altering the ultrasmall particle size (≈2.7–2.8 nm). Evidently, this cation‐doping strategy facilitates both the renovation of crystal structure of Ag2S QDs and modulation of their optical properties.
Both the crystal structure and optical properties of narrow bandgap semiconductor Ag2S QDs have a revolutionary change upon the doping of transition metal Pb2+ ions. The ultrasmall size (≈2.7–2.8 nm), bright tunable emission (975–1242 nm), excellent stability and decent biocompatibility of the Pb‐doped Ag2S QDs render this material a promising application prospect in in vivo fluorescence‐based imaging.
The accumulation of lipid peroxides is recognized as a determinant of the occurrence of ferroptosis. However, the sensors and amplifying process of lipid peroxidation linked to ferroptosis remain ...obscure. Here we identify PKCβII as a critical contributor of ferroptosis through independent genome-wide CRISPR-Cas9 and kinase inhibitor library screening. Our results show that PKCβII senses the initial lipid peroxides and amplifies lipid peroxidation linked to ferroptosis through phosphorylation and activation of ACSL4. Lipidomics analysis shows that activated ACSL4 catalyses polyunsaturated fatty acid-containing lipid biosynthesis and promotes the accumulation of lipid peroxidation products, leading to ferroptosis. Attenuation of the PKCβII-ACSL4 pathway effectively blocks ferroptosis in vitro and impairs ferroptosis-associated cancer immunotherapy in vivo. Our results identify PKCβII as a sensor of lipid peroxidation, and the lipid peroxidation-PKCβII-ACSL4 positive-feedback axis may provide potential targets for ferroptosis-associated disease treatment.
Metal-organic frameworks (MOFs) derived carbon-based composites exhibit great potential in the fields of electromagnetic wave (EMW) absorption. However, which kind of MOFs derivative structure has ...better electromagnetic wave absorption is an urgent problem to be addressed. Herein, caterpillar-like hierarchically structured Co/MnO/CNTs was successfully prepared by pyrolysis of core-shell manganese dioxide and zeolitic imidazolate framework template. The material shows excellent EMW absorption performance in different frequencies range based on the hierarchical structure. Owing to the unique distribution of carbon nanotubes on the caterpillar-like hierarchical structure, the generated multi heterogeneous interfaces and local conductive network are beneficial to interfacial polarization, conduction loss, matched impedance as well as multiple scattering. The composite composites present outstanding EMW absorption achieved with effective absorption bandwidth covering from 13.52 GHz to 18 GHz with thickness of only 1.32 mm. Moreover, the composite also demonstrates a microwave absorption with the qualified frequency bandwidth of 5.36 GHz, and a strong reflection loss of −58.0 dB with a low filling amount of 35%. The result provides a new approach for developing EMW absorbing materials with hierarchical structure.
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•The caterpillar-like hierarchical structure composed of carbon nanotubes was prepared.•The composites have wide microwave absorption bandwidth and strong reflection loss.•The hierarchical material has the advantage in broadband impedance matching design.
Electrical conductivity and dielectric parameters are general inherent features of materials. Controlling these characteristics through applied bias will add a new dimension to regulate the dynamic ...response of smart materials. Here, a fascinating electrical transport behavior is observed in topological insulator (TI) Bi2Te3 nanorods, which will play a vital role in intelligent materials or devices as a unit for information reception, processing or feedback. The Bi2Te3 nanorod aggregates exhibit a monotonic resistance response to voltage, with observed four‐fold change of electrical conductivity in a small range electric field of 1 V mm−1. The dielectric constant and dielectric loss of Bi2Te3 nanorod composites also show strong dependences on bias voltage due to the unique electrical transport characteristics. The unique voltage‐controlled electrical responses are attributed to the change of Fermi levels within the band structure of disordered TI nanorods, which are non‐parallel to the applied electric field. The excellent controllable inherent characteristics through electric field endows Bi2Te3 nanomaterials bright prospects for applications in smart devices and resistive random access memories.
Bi2Te3 nanorods exhibit monotonic resistance response to voltage and strong dependence of dielectric constant on voltage. Compared with other materials, the Bi2Te3 nanorod aggregates have the largest electrical conductivity variation range with smallest voltage scope. The fascinating electrical transport behavior endows the material with tremendous application potential in communication systems, smart devices, miniature generators, and intelligent storage.
Rapid detection of highly contagious pathogens is the key to increasing the probability of survival and reducing infection rates. We developed a sensitive and quantitative lateral flow assay for ...detection of Ebola virus (EBOV) glycoprotein with a novel multifunctional nanosphere (RNs@Au) as a reporter. Each RNs@Au contains hundreds of quantum dots and dozens of Au nanoparticles and can achieve enhanced dual-signal readout (fluorescence signal for quantitative detection and colorimetric signal for visual detection). Antibody (Ab) and streptavidin (SA) were simultaneously modified onto the RNs@Au to label the target and act as signal enhancer. After the target was labeled by the Ab–RNs@Au–SA and captured on the test line, biotin-modified RNs@Au was used to amplify the dual signal by the reaction of SA with biotin. The assay enables naked-eye detection of 2 ng/mL glycoprotein within 20 min, and the quantitative detection limit is 0.18 ng/mL. Additionally, the assay has been successfully tested in field work for detecting EBOV in spiked urine, plasma, and tap water samples and is thus a promising candidate for early diagnosis of suspect infections in EBOV-stricken areas.
Most patients with triple negative breast cancer (TNBC) do not respond to anti-PD1/PDL1 immunotherapy, indicating the necessity to explore immune checkpoint targets. B7H3 is a highly glycosylated ...protein. However, the mechanisms of B7H3 glycosylation regulation and whether the sugar moiety contributes to immunosuppression are unclear. Here, we identify aberrant B7H3 glycosylation and show that N-glycosylation of B7H3 at NXT motif sites is responsible for its protein stability and immunosuppression in TNBC tumors. The fucosyltransferase FUT8 catalyzes B7H3 core fucosylation at N-glycans to maintain its high expression. Knockdown of FUT8 rescues glycosylated B7H3-mediated immunosuppressive function in TNBC cells. Abnormal B7H3 glycosylation mediated by FUT8 overexpression can be physiologically important and clinically relevant in patients with TNBC. Notably, the combination of core fucosylation inhibitor 2F-Fuc and anti-PDL1 results in enhanced therapeutic efficacy in B7H3-positive TNBC tumors. These findings suggest that targeting the FUT8-B7H3 axis might be a promising strategy for improving anti-tumor immune responses in patients with TNBC.
Comprehensive phenotypic profiling of heterogeneous circulating tumor cells (CTCs) at single‐cell resolution has great importance for cancer management. Herein, a novel spectrally combined encoding ...(SCE) strategy was proposed for multiplex biomarker profiling of single CTCs using a multifunctional nanosphere‐mediated microfluidic platform. Different cellular biomarkers uniquely labeled by multifunctional nanosphere barcodes, possessing identical magnetic tags and distinct optical signatures, enabled isolation of heterogeneous CTCs with over 91.6 % efficiency and in situ SCE of phenotypes. By further trapping individual CTCs in ordered microstructures on chip, composite single‐cell spectral signatures were conveniently and efficiently obtained, allowing reliable spectral‐readout for multiplex biomarker profiling. This SCE strategy exhibited great potential in multiplex profiling of heterogeneous CTC phenotypes, offering new avenues for cancer study and precise medicine.
A spectrally combined encoding strategy was proposed for multiplex biomarker profiling of heterogeneous circulating tumor cells (CTCs) using a multifunctional nanosphere‐mediated microfluidic platform. Different cellular biomarkers simultaneously encoded with both magnetic tags and distinct optical signatures, enabled efficient isolation and in situ on‐chip spectrally combined encoding of heterogeneous CTCs at single‐cell resolution.
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