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Covalent organic frameworks (COFs) are attractive adsorbents for sample pretreatment due to their unique structure and properties. However, the selectivity of COFs for the extraction of hazardous compounds is still limited due to the lack of specific interactions between COFs and targets. Herein, we report a pore size adjustment strategy for room-temperature synthesis of molecularly imprinted COF (MICOF) for selective extraction of zearalenone (ZEN) in complex food samples. The three-dimensional building block tetra(4-aminophenyl) methane was used as a functional monomer, while dialdehyde monomers with different numbers of benzene ring were used to adjust the pore size of MICOF to match with the size of ZEN molecules. The prepared MICOF gave the largest adsorption capacity of 177.2 mg g-1 and the highest imprinting factor of 10.1 for ZEN so far. MICOF was used as the adsorbent for dispersed solid-phase extraction in combination with high-performance liquid chromatography for the determination of trace ZEN in cereals. The high selectivity of the developed method allows simple aqueous standard calibration for the matrix effect-free determination of ZEN in food samples. The limit of detection and the recoveries of the developed method were 0.21 µg kg-1 and 93.7-101.4%, respectively. The precision for the determination of ZEN was less than 3.8% (RSD, n = 6). The developed method is promising for the selective determination of ZEN in complex matrices.
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Estruturas Metalorgânicas , Nanosferas , Zearalenona , Estruturas Metalorgânicas/química , Zearalenona/análise , Grão Comestível/química , Temperatura , Cromatografia Líquida de Alta Pressão/métodos , Extração em Fase Sólida/métodos , AdsorçãoRESUMO
The uptake of plastic particles by plants and their transport through the food chain make great risks to biota and human health. Therefore, it is important to trace plastic particles in the plant. Traditional fluorescence imaging in plants usually suffers significant autofluorescence background. Here, we report a persistent luminescence nanoplatform for autofluorescence-free imaging and quantitation of submicrometer plastic particles in plant. The nanoplatform was fabricated by doping persistent luminescence nanoparticles (PLNPs) onto polystyrene (PS) nanoparticles. Cr3+-doped zinc gallate PLNP was employed as the dopant for autofluorescence-free imaging due to its persistent luminescence nature. In addition, the Ga element in PLNP was used as a proxy to quantify the PS in the plant by inductively coupled plasma mass spectrometry (ICP-MS). Thus, the developed nanoplatform allows not only dual-mode autofluorescence-free imaging (persistent luminescence and laser-ablation ICP-MS) but also ICP-MS quantitation for tracking PS in plant. Application of this nanoplatform in a typical plant model Arabidopsis thaliana revealed that PS mainly distributed in the root (>99.45%) and translocated very limited (<0.55%) to the shoot. The developed nanoplatform has great potential for quantitative tracing of submicrometer plastic particles to investigate the environmental process and impact of plastic particles.
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Arabidopsis , Nanopartículas , Arabidopsis/química , Nanopartículas/química , Luminescência , Plásticos/química , Tamanho da Partícula , Poliestirenos/química , Imagem ÓpticaRESUMO
Understanding the individual fluorescence response mechanism of covalent organic frameworks (COFs) at a single-crystal level is of great significance for the rational design of COF-based microsensors but unreachable because all previous COF-based sensors are performed with average fluorescence response behavior of various sized polycrystalline COFs. Herein, we design to explore the fluorescence response of a monodisperse single-crystal COF and further reveal the individual heterogeneity of the response mechanism. Three-dimensional single-crystal COF-301 (SCOF-301) with an intramolecular H-bond-induced excited-state intramolecular proton-transfer effect is selected as a proof-of-concept SCOF. With ethanol, benzene, and ammonia as model analytes, three different deformation and competition H-bond site-induced fluorescence response mechanisms related to crystal size are revealed. Small single particles of SCOF-301 (SSCOF-301) exhibit a more flexible structure, leading to the dominant role of deformation in the fluorescence response of small-sized SSCOF-301. The decreasing flexibility of SSCOF-301 with the increase of crystal size results in involvement of competition of the H-bond site to the fluorescence response besides deformation. Further increase of the crystal size makes the large-sized SSCOF-301 difficult to deform; thus, the competition of the H-bond site dominates the fluorescence response. This work provides a deep understanding of the individual fluorescence response mechanism of COFs to guide the design of a functional COF sensor with suitable size and mechanism for different structural analytes.
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It is usually believed that doping with photosensitizers capable of generating singlet oxygen (1O2) plays a pivotal role in enhancing the afterglow performance of semiconducting polymer nanoparticles (SPNs). However, the effect of doping photosensitizer bearing electron-withdrawing groups has not been reported. Here we report the effect of doping with six photosensitizers possessing different electron-withdrawing groups on the afterglow performance of SPNs using poly[(9,9-di(2-ethylhexyl)-9H-fluo-rene-2,7-vinylene)-co-(1-methoxy-4-(2-ethylhexyloxy)-2,5-phenylenevinylene)] (PF-MEHPPV) as substrate. It was found that the afterglow performance of SPNs was significantly influenced by doping with photosensitizers bearing electron-withdrawing groups. For the doped photosensitizers with strong electron-withdrawing groups, the stronger the electron-withdrawing ability of the group, the worse of the afterglow performance of the SPN regardless of the 1O2 generation ability of the photosensitizer. When the doped photosensitizer exhibited weak or none electron-withdrawing effect, the 1O2 generation ability of the photosensitizer played a dominant role on the afterglow performance of the SPNs. This work deepens the understanding of the design and synthesis of SPNs with different afterglow properties.
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BACKGROUND: The association of hypertension and depression with mortality has not been fully understood. We aimed to explore the possible independent or joint association of hypertension and depression with mortality. Their interaction effects on mortality and possible mediating role were also investigated. METHODS: Associations of hypertension, depression, and their interaction with all-cause and cardiovascular disease (CVD) mortality were evaluated using multivariate Cox proportional hazards regression models. The mediation analysis was conducted with a Sobel test. RESULTS: A total of 35152 participants were included in the final analysis. Hypertension and depression were independently associated with increased risk of all-cause and CVD mortality. The co-existence of hypertension and depression resulted in a 1.7-fold [95% confidence interval (CI): 1.3-2.1] increase in all-cause mortality and a 2.3-fold (95% CI: 1.4-3.7) increase in CVD mortality compared to those with neither of them. Hypertension and depression showed no significant multiplicative (P for interaction, 0.587) and additive interaction (P for relative excess risk of interaction, 0.243; P for Interaction on additive scale, 0.654) on all-cause mortality, as well as on CVD mortality. Depression did not mediate the relationship between hypertension and all-cause (Z=1.704, P=0.088) and CVD mortality (Z=1.547, P=0.122). Hypertension did not mediate the relationship between all-cause and CVD mortality as well. CONCLUSION: Hypertension and depression were related to all-cause and CVD mortality independently and the co-existence of them increased the risk of mortality. However, there is no interaction effect of them on mortality, and hypertension or depression did not mediate the association of each other with mortality.
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Doenças Cardiovasculares , Hipertensão , Humanos , Depressão/complicações , Hipertensão/complicações , Risco , Modelos de Riscos Proporcionais , Fatores de RiscoRESUMO
Cell cycle is a significant factor toward cellular heterogeneity, so cell cycle discrimination is a precise measurement on the top of single-cell analysis. Single-cell analysis based on organic mass spectrometry has received great attention for its unique ability to profile single-cell metabolome, but the influence of cell cycle on cellular metabolome heterogeneity has been overlooked until now due to the lack of a compatible cell cycle discrimination method. Here, we report a robust protocol based on the combination of three small molecular indicators, consisting of two small molecular labels (Hoechst and docetaxel) and one cellular endogenous compound [phosphocholine (34:1)], to discriminate single cells at different cycle stages in real time by organic mass cytometry. More than 6000 HeLa cells were acquired by an improved organic mass cytometry system to build a cell cycle differentiation model. The model successfully discriminated single HeLa cells, SCC7, and Hep G2 cells, at G0/G1, S, and G2/M stages with larger than 85% sensitivity and larger than 89% specificity. Along with cell cycle discrimination, obvious heterogeneity of amino acids, nucleotides, energy metabolic intermediates, and phospholipids was observed among single cells at different cycle stages by this protocol, further demonstrating the necessity of cell cycle discrimination for cellular metabolome heterogeneity research and the potential of more endogenous small molecular compounds for cell cycle discrimination.
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Metaboloma , Humanos , Células HeLa , Ciclo Celular , Divisão Celular , Espectrometria de Massas , Citometria de FluxoRESUMO
Although polycrystalline covalent organic frameworks (PCOFs) have already shown great potential as stationary phases for chromatography, irregular shape and size distribution of PCOFs make regulation of particle size of PCOFs for high separation performance impossible, which is accessible by the application of single-crystalline COFs (SCOFs). Herein, we showed preparation of three-dimensional SCOF (SCOF-303) bonded capillaries (SCOF-303-capillary) with different particle sizes (about 0.4-1.6 µm) and further investigated gas chromatographic separation ability of these SCOF-303-capillaries for isomers of xylene, dichlorobenzene, and pinene. It was found resolution and column efficiency of SCOF-303-capillaries for isomers decreased with the increase in particle size, mainly resulting from the weaker size-exclusion effect and higher mass transfer resistance of the larger particle size of flexible SCOF-303. The obtained SCOF-303-capillary (particle size of â¼0.4 µm) offered baseline separation of xylene isomers with the high resolution of 2.26-3.52, great efficiency of 7879 plates m-1 for p-xylene, better than PCOF-303-capillary, and commercial DB-5 and HP-FFAP capillary columns as well as many reported capillaries. This work not only shows the great potential of SCOFs for gas chromatography but also provides the theoretical direction for the design of the efficient COF based stationary phase by adjusting the particle sizes.
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On-skin electronics based on impermeable elastomers and stacking structures often suffer from inferior sweat-repelling capabilities and severe mechanical mismatch between sub-layers employed, which significantly impedes their lengthy wearing comfort and functionality. Herein, inspired by the transpiration system of vascular plants and the water diode phenomenon, a hierarchical nonwoven electronic textile (E-textile) with multi-branching microfibers and robust interlayer adhesion is rationally developed. The layer-by-layer electro-airflow spinning method and selective oxygen plasma treatment are utilized to yield a porosity-hydrophilicity dual-gradient. The resulting E-textile shows unidirectional, nonreversible, and anti-gravity water transporting performance even upon large-scale stretching (250%), excellent mechanical matching between sub-layers, as well as a reversible color-switching ability to visualize body temperature. More importantly, the conducting and skin-conformal E-textile demonstrates accurate and stable detecting capability for biomechanical and bioelectrical signals when applied as an on-skin bioelectrode, including different human activities, electrocardiography, electromyogram, and electrodermal activity signals. Further, the E-textile can be efficiently implemented in human-machine interfaces to build a gesture-controlled dustbin and a smart acousto-optic alarm. Hence, this hierarchically-designed E-textile with integrated functionalities offers a practical and innovative method for designing comfortable and daily applicable on-skin electronics.
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Dispositivos Eletrônicos Vestíveis , Humanos , Suor , Temperatura Corporal , Temperatura , Porosidade , Têxteis , Eletrônica , Interações Hidrofóbicas e HidrofílicasRESUMO
BACKGROUND: Both physical activity and dysglycemia are associated with depression. However, the combined association of adherence to recommended physical activity (RPA) and glycemic control with depression is unknown. Moreover, the extent to which glycemic control mediates the association between physical activity and depression is not established. METHODS: The sample included 31,302 adults from the National Health and Nutrition Examination Survey 2007-08 to 2017-18. Adherence to RPA for aerobic activity was defined according to the WHO 2020 guidelines. HbA1c was classified as < 5.7%, 5.7-6.4%, 6.5-6.9%, and ≥ 7.0%. Depression was evaluated according to the 9-item Patient Health Questionnaire. The odds ratio for depression stratified by adherence to RPA and HbA1c level were estimated by logistic regressions. Mediation analysis was performed to estimate the direct associations (not through glycemic control) and indirect associations (through glycemic control). RESULTS: A total of 2871 participants were diagnosed with depression. Compared to participants with HbA1c level < 5.7% who adhere to RPA, those with HbA1c level < 5.7%, 5.7-6.4%, 6.5-6.9%, and ≥ 7.0% who did not adhere to RPA had increased odds ratio for depression, especially in women and older adults. Individuals with HbA1c ≥ 7.0% still had an increased odds ratio for depression even though they were physically active. The results of the mediation analysis were insignificant. CONCLUSION: There was a combined association of adherence to RPA and glycemic control with depression in women and older adults. We did not find out evidence of glycemic control mediation on the pathway from physical activity to depression.
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Diabetes Mellitus Tipo 2 , Humanos , Feminino , Idoso , Diabetes Mellitus Tipo 2/complicações , Hemoglobinas Glicadas , Glicemia/metabolismo , Depressão/epidemiologia , Inquéritos Nutricionais , Controle Glicêmico , Exercício FísicoRESUMO
Grafting specific recognition moieties onto solid-state nanofluidic channels is a promising way for selective and sensitive sensing of analytes. However, the time-consuming interaction between recognition moieties and analytes is the main hindrance to the application of nanofluidic channel-based sensors in rapid detection. Here, we show the integration of ordered two-dimensional covalent organic frameworks (2D COFs) to solid-state nanofluidic channels to achieve rapid, selective, and sensitive detection of contaminants. As a proof of concept, a thiourea-linked 2D COF (JNU-3) as the recognition unit is covalently bonded on the stable artificial anodic aluminum oxide nanochannels (AAO) to fabricate a JNU-3@AAO-based nanofluidic sensor. The rapid and selective interaction of Hg(II) with the highly ordered channels of JNU-3 allows the JNU-3@AAO-based nanofluidic sensor to realize ultrafast and precise determination of Hg(II) (90 s) with a low limit of detection (3.28 fg mL-1), wide linear range (0.01-100 pg mL-1), and good precision (relative standard deviation of 3.8% for 11 replicate determination of 10 pg mL-1). The developed method was successfully applied to the determination of mercury in a certified reference material A072301c (rice powder), real water, and rice samples with recoveries of 90.4-99.8%. This work reveals the great potential of 2D COFs-modified solid-state nanofluidic channels as a sensor for the rapid and precise detection of contaminants in complicated samples.
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Mercúrio , Estruturas Metalorgânicas , ÁguaRESUMO
Sensitive and accurate determination of aflatoxin B1 (AFB1) is of great significance to food safety and human health as it is recognized as the most toxic mycotoxin and carcinogenic. Herein, we report a ratiometric luminescence aptasensor based on dual-emissive persistent luminescent nanoparticles (PLNP) for the accurate determination of trace AFB1 in complex food samples without autofluorescence and exogenous interference. Dual-emissive PLNP ZnGa2O4:Cr0.0001 was prepared first and acted as the donor for energy transfer as well as the signal unit with phosphorescence at 714 and 508 nm (the detection and the reference signal, respectively). AFB1 aptamer was then bonded on the surface of PLNP to offer specific recognition ability. Aptamer complementary DNA modified with Cy5.5 was employed as the acceptor for energy transfer and the quenching group to eventually develop a turn-on ratiometric luminescence aptasensor. The developed ratiometric luminescence aptasensor combined the merits of long-lasting luminescence, in situ excitation and autofluorescence-free of PLNP, exogenous interference-free and self-calibration reading of ratiometric sensor, as well as the high selectivity of aptamer, holding great promise for accurate determination of trace AFB1 in complex matrix. The developed ratiometric aptasensor exhibited excellent linearity (0.05-70 ng mL-1), low limit of detection (0.016 ng mL-1), and good precision (2.3% relative standard deviation for 11 replicate determination of 1 ng mL-1 AFB1). The proposed ratiometric aptasensor was successfully applied for the determination of AFB1 in corn, wheat, peanut, millet, oats, and wheat kernels with recoveries of 95.1-106.5%.
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Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Aflatoxina B1/análise , Humanos , Limite de Detecção , LuminescênciaRESUMO
Mass spectrometry (MS) is attractive for single-cell analysis because of its high sensitivity, rich information, and large dynamic ranges, especially for the single-cell metabolome and proteome analysis. Efforts have been made to deal with the throughput and information coverage problems in typical manual single-cell MS techniques. In this review, advanced techniques to improve the automation and throughput for single-cell sampling and single-cell metabolome and proteome MS detection have been discussed. Furthermore, representative MS-based strategies that can increase the in-depth cellular information coverage and achieve the more comprehensive single-cell multiomics information during high throughput detection have been highlighted, providing an ongoing perspective of the MS performance for the single-cell research.
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Ensaios de Triagem em Larga Escala , Espectrometria de Massas/métodos , Metabolômica/métodos , Proteômica/métodos , Análise de Célula Única/métodosRESUMO
The separation of amino acid (AA) enantiomers shows significance for chemistry, food, and biology, but remains challenging due to their similar properties. A promising nanoporous chiral covalent organic framework (COF) as a stationary phase for high-performance liquid chromatography (HPLC) suffers from the irregularity and widely distributed particle size of the chiral COF. Herein, we show the facile preparation of a chiral COF-monolith as a stationary phase for HPLC enantiomeric separation of AAs via orthogonal experiments. The CTzDa-monolith is prepared by the incorporation of the model chiral COF named CTzDa into the porous poly(ethylene dimethacrylate-co-methacrylate) monolith and reveals great permeability and mechanical stability. The corresponding CTzDa-monolithic column gives better chiral HPLC separation of AAs than the commercial Poroshell 120 chiral-T column. Thermal dynamic analysis and molecular docking calculations imply the involvement of stereoscopic hydrogen, π-π, and van der Waals interactions between the CTzDa and AAs during HPLC enantioseparation. The facile incorporation of the chiral COF into the porous monolith will promote the potential of a chiral COF as a stationary phase for HPLC.
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Estruturas Metalorgânicas , Aminas , Aminoácidos/química , Cromatografia Líquida de Alta Pressão/métodos , Simulação de Acoplamento Molecular , EstereoisomerismoRESUMO
BACKGROUND: The relationship between the coexistence of depression and moderate chronic kidney disease (CKD) and mortality is unclear. We aimed to investigate whether there is a synergistic effect of depression and moderate CKD on the all-cause and cardiovascular disease (CVD) mortality among adults. METHODS: We studied 24,412 participants from the National Health and Nutrition Examination Survey 2005-2014 with a mortality follow-up assessment in 2015. Four groups were created based on depression and CKD status: Group 1, no depression and no CKD; Group 2, depression present and no CKD; Group 3: no depression and CKD present; Group 4: depression present and CKD present. Moderate CKD was defined as an estimated glomerular filtration rate of 15-59 mL/min/1.73 m2 (Stage 3-4) or one-time urine albumin-to-creatinine ratio ≥ 30 mg/g. Depression was defined as the 9-item Patient Health Questionnaire score of 10 or more. Cox proportional hazards regression models were used to calculate the multivariate-adjusted hazard ratios (HRs) of death for Group 4 with other groups. RESULTS: Over a mean follow-up of 5.8 years, 1783 deaths were documented, including 338 deaths from CVD. The HR for all-cause mortality in Group 4 was 3.62 (95% CI: 2.69-4.87), 2.99 (1.92-4.66), and 1.75 (1.29-2.37) when compared with Group 1, 2, and 3, respectively. The HR for CVD mortality in Group 4 was 3.89 (1.68-9.00), 1.90 (0.86-4.21), and 1.97 (1.17-3.32) when compared with Group 1, 2, and 3, respectively. CONCLUSIONS: There might be a synergistic effect of depression and moderate CKD on all-cause mortality. Moreover, depression might increase the risk of CVD mortality in individuals with moderate CKD.
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Doenças Cardiovasculares , Insuficiência Renal Crônica , Adulto , Albuminas , Creatinina/urina , Taxa de Filtração Glomerular , Humanos , Inquéritos Nutricionais , Insuficiência Renal Crônica/diagnóstico , Estudos Retrospectivos , Fatores de RiscoRESUMO
Mass spectrometry combined with flow cytometry is emerging for high-throughput single-cell metabolite analysis but still has problems with limited intracellular information coverage. Here, we show a simple and efficient all-in-one system integrating cell injection, cell extraction, online cell lysis, analyte ionization, and mass spectrometric detection for rapid single-HeLa-cell screening with in-depth profiling of cellular metabolites and drugs. Zinc oxide nanothorn-decorated filters with three bore sizes (5.22, 8.36, and 16.75 µm) were fabricated for efficient online lysis of the cell membrane (even nuclear membrane) to facilitate intracellular analyte release and demonstrated to have a size effect for potential subcellular discrimination. The two smaller-bore filters gave 2-11-fold improvements in signal response for representative intracellular metabolites, such as adenosine, glutamine, and leucine/isoleucine. Especially, the smallest-bore filter enabled successful detection of the metabolites in the nucleus, including tetrahydrobiopterin and cyclic guanosine monophosphate. The developed all-in-one system was explored to monitor the uptake of four anticancer drugs, including 5-fluorouracil, doxorubicin, gambogic acid, and paclitaxel in single cells, and further to investigate the drug uptake trends at the subcellular level. The all-in-one system integrates the merits of high-throughput single-cell screening and in-depth intracellular information profiling and is promising for high-coverage single-cell metabolome analysis to serve cell biology research and cancer research.
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Antineoplásicos , Metaboloma , Doxorrubicina , Humanos , Espectrometria de Massas , Análise de Célula ÚnicaRESUMO
Sensitive and precise determination of chloramphenicol (CAP) is of great significance for human health due to its high risk in trace amounts. Solid-state artificial nanochannels are expected to be highly promising sensing devices owing to single-molecule sensitivity, target-specific selectivity, and portability. Herein, we report an aptamer self-assembly-functionalized artificial nanochannel-based sensor for highly sensitive and precise determination of CAP. Aptamer self-assembly (AAs) served as the specific recognition component and were in situ grown on the surface of stable anodic aluminum oxide (AAO) nanochannels to develop an AAs@AAO nanochannel-based sensor. Selective interaction with CAP led to the disassembly of AAs and sensitive current change of AAs@AAO nanochannels, allowing sensitive and precise sensing of CAP in complex food samples. The developed AAs@AAO nanochannel-based sensor showed a wide linear range from 0.32 to 1600 pg. mL-1, low limit of detection (LOD) of 0.1 pg. mL-1, high precision with relative standard deviation of 2.9%, and quantitative recoveries of 93.4-102.2% for CAP in milk, milk powder, and honey samples. This work proposes a versatile nanochannel-based platform for facile, sensitive, and precise sensing of hazardous residues in food samples.
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Técnicas Biossensoriais , Mel , Animais , Cloranfenicol/análise , Eletrodos , Mel/análise , Humanos , Limite de Detecção , Leite/químicaRESUMO
Persistent luminescence nanoparticles (PLNPs) hold great promise for bioimaging owing to no demand for in situ excitation and negligible tissue autofluorescence interference. Nevertheless, huge challenges remain in the further development of single-emissive PLNPs due to the great variation of luminescence with time after excitation ceases. Herein, we report the controllable fabrication of dual-emissive monodispersed PLNPs (ZnGa2O4:Cr) by a surfactant-assisted hydrothermal method in combination with postcalcination for bioimaging. The prepared PLNPs emit luminescence at 508 and 714 nm with a constant luminescence ratio (I508/I714) for more than 1 h after UV excitation stops. Moreover, the prepared PLNPs give a constant I508/I714 ratio signal after repeated excitation by a LED lamp, allowing luminescence ratio imaging to ensure the long-term accuracy for in vivo imaging. In vivo ratio imaging demonstrates the potential of the prepared PLNPs for precision bioimaging. In addition, the prepared PLNPs have been applied to fabricate a theranostic nanoprobe with intelligent tumor-targeted imaging and chemo-photothermal synergistic therapy to further reveal their unique advantage for imaging guided therapy. We believe that the dual-emissive PLNPs will provide a promising nanoplatform for bioimaging and biomedical applications.
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Nanopartículas , Neoplasias , Diagnóstico por Imagem , Humanos , LuminescênciaRESUMO
Selective and sensitive determination of trace kanamycin in complex food samples is of great importance for food safety because of its high toxicity. Here, we report a sensitive and autofluorescence-free persistent luminescence (PL) aptasensor for selective, sensitive, and autofluorescence-free determination of kanamycin in food samples. The aptamer for kanamycin was first conjugated onto the surface of magnetic nanoparticles Fe3O4 to serve as the recognition unit as well as the separation element, while the PL nanoparticles ZnGa2O4:Cr (PLNPs) were functionalized with the aptamer complementary DNA (cDNA) as the PL signal. The PL aptasensor consisted of the aptamer-conjugated MNPs (MNPs-apt) and cDNA-functionalized PLNPs (PLNPs-cDNA) and combined the merits of the long-lasting luminescence of PLNPs, the magnetic separation ability of MNPs as well as the selectivity of the aptamer, offering a promising approach for autofluorescence-free determination of kanamycin in food samples. The proposed aptasensor showed excellent linearity in the range from 1 pg mL-1 to 5 ng mL-1 with a limit of detection of 0.32 pg mL-1. The precision for 11 replicate determinations of 100 pg mL-1 kanamycin was 3.1% (relative standard deviation). The developed aptasensor was applied for the determination of kanamycin in milk and honey samples with the recoveries of 95.4-106.3%. The proposed aptasensor is easily extendable to other analytes by simply replacing the aptamer, showing great potential as a universal aptasensor platform for selective, sensitive, and autofluorescence-free detection of hazardous analytes in food samples.
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Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Canamicina/química , Medições Luminescentes/métodos , Animais , Técnicas Biossensoriais , Compostos Ferrosos , Mel/análise , Nanopartículas Metálicas , Leite/química , Pós/químicaRESUMO
Porphyrinic metal-organic frameworks (MOFs) are promising photosensitizers due to the lack of self-aggregation of porphyrin in aqueous solution. However, how the topology of porphyrinic MOFs affects the generation of singlet oxygen (1 O2 ) is unclear. Here, the effect of the topology of porphyrinic MOFs on their photodynamic performance is reported. Four porphyrinic zirconium MOFs (MOF-525, MOF-545, PCN-223 and PCN-224 with different topologies: ftw, csq, shp and she, respectively) were selected to study the influence of topology on the photodynamic antibacterial performance. The 1 O2 generation and the photodynamic antibacterial performance followed an decreasing order of MOF-545>MOF-525>PCN-224>PCN-223. The results reveal that the pore size, the distance between porphyrin, and the number of porphyrin per Zr6 O8 cluster in MOFs greatly affected 1 O2 generation. This work provides guidance for designing new MOFs for efficient photodynamic sterilization.
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Estruturas Metalorgânicas , Porfirinas , Fármacos Fotossensibilizantes , Esterilização , ZircônioRESUMO
Persistent luminescent nanoparticles (PLNPs) with intrinsic stimuli-responsive properties are desirable because of no autofluorescence background and natural responsive luminescence. However, the stimuli-responsive features of pure PLNPs have been unexplored. Here we show a facile one-pot hydrothermal synthesis of green-emitting Zn2 GeO4 :Mn2+ ,Pr3+ nanoparticles (ZGMP) with regular shape, uniform size and good afterglow luminescent performance. We also report the pH stimuli-responsive luminescent behavior of ZGMP and its possible mechanism. Taking the intriguing feature of pH responsive persistent luminescence, we explore ZGMP as autofluorescence-free probes to achieve stimuli-activated signal switch for biosensing by integrating enzyme catalysis reaction mediated pH modulation. The pH-responsive persistent luminescence also makes ZGMP promising for high-level information encryption.