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1.
Proc Natl Acad Sci U S A ; 121(17): e2320777121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38630719

RESUMO

The hybrid electrolyzer coupled glycerol oxidation (GOR) with hydrogen evolution reaction (HER) is fascinating to simultaneously generate H2 and high value-added chemicals with low energy input, yet facing a challenge. Herein, Cu-based metal-organic frameworks (Cu-MOFs) are reported as model catalysts for both HER and GOR through doping of atomically dispersed precious and nonprecious metals. Remarkably, the HER activity of Ru-doped Cu-MOF outperformed a Pt/C catalyst, with its Faradaic efficiency for formate formation at 90% at a low potential of 1.40 V. Furthermore, the hybrid electrolyzer only needed 1.36 V to achieve 10 mA cm-2, 340 mV lower than that for splitting pure water. Theoretical calculations demonstrated that electronic interactions between the host and guest (doped) metals shifted downward the d-band centers (εd) of MOFs. This consequently lowered water adsorption and dissociation energy barriers and optimized hydrogen adsorption energy, leading to significantly enhanced HER activities. Meanwhile, the downshift of εd centers reduced energy barriers for rate-limiting step and the formation energy of OH*, synergistically enhancing the activity of MOFs for GOR. These findings offered an effective means for simultaneous productions of hydrogen fuel and high value-added chemicals using one hybrid electrolyzer with low energy input.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38605232

RESUMO

RATIONALE: The mechanisms underlying major depressive disorder (MDD) in children and adolescents are unclear. Metabolomics has been utilized to capture metabolic signatures of various psychiatric disorders; however, urinary metabolic profile of MDD in children and adolescents has not been studied. OBJECTIVES: We analyzed urinary metabolites in children and adolescents with MDD to identify potential biomarkers and metabolic signatures. METHODS: Here, liquid chromatography-mass spectrometry was used to profile metabolites in urine samples from 192 subjects, comprising 80 individuals with antidepressant-naïve MDD (AN-MDD), 37 with antidepressant-treated MDD (AT-MDD) and 75 healthy controls (HC). We performed orthogonal partial least squares discriminant analysis to identify differential metabolites and employed logistic regression and receiver operating characteristic analysis to establish a diagnostic panel. RESULTS: In total, 143 and 71 differential metabolites were identified in AN-MDD and AT-MDD, respectively. These were primarily linked to lipid metabolism, molecular transport, and small molecule biochemistry. AN-MDD additionally exhibited dysregulated amino acid metabolism. Compared to HC, a diagnostic panel of seven metabolites displayed area under the receiver operating characteristic curves of 0.792 for AN-MDD, 0.828 for AT-MDD, and 0.799 for all MDD. Furthermore, the urinary metabolic profiles of children and adolescents with MDD significantly differed from those of adult MDD. CONCLUSIONS: Our research suggests dysregulated amino acid metabolism and lipid metabolism in the urine of children and adolescents with MDD, similar to results in plasma metabolomics studies. This contributes to the comprehension of mechanisms underlying children and adolescents with MDD.

3.
Transl Psychiatry ; 14(1): 163, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38531835

RESUMO

Major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SCZ) are classified as major mental disorders and together account for the second-highest global disease burden, and half of these patients experience symptom onset in adolescence. Several studies have reported both similar and unique features regarding the risk factors and clinical symptoms of these three disorders. However, it is still unclear whether these disorders have similar or unique metabolic characteristics in adolescents. We conducted a metabolomics analysis of plasma samples from adolescent healthy controls (HCs) and patients with MDD, BD, and SCZ. We identified differentially expressed metabolites between patients and HCs. Based on the differentially expressed metabolites, correlation analysis, metabolic pathway analysis, and potential diagnostic biomarker identification were conducted for disorders and HCs. Our results showed significant changes in plasma metabolism between patients with these mental disorders and HCs; the most distinct changes were observed in SCZ patients. Moreover, the metabolic differences in BD patients shared features with those in both MDD and SCZ, although the BD metabolic profile was closer to that of MDD than to SCZ. Additionally, we identified the metabolites responsible for the similar and unique metabolic characteristics in multiple metabolic pathways. The similar significant differences among the three disorders were found in fatty acid, steroid-hormone, purine, nicotinate, glutamate, tryptophan, arginine, and proline metabolism. Interestingly, we found unique characteristics of significantly altered glycolysis, glycerophospholipid, and sphingolipid metabolism in SCZ; lysine, cysteine, and methionine metabolism in MDD and BD; and phenylalanine, tyrosine, and aspartate metabolism in SCZ and BD. Finally, we identified five panels of potential diagnostic biomarkers for MDD-HC, BD-HC, SCZ-HC, MDD-SCZ, and BD-SCZ comparisons. Our findings suggest that metabolic characteristics in plasma vary across psychiatric disorders and that critical metabolites provide new clues regarding molecular mechanisms in these three psychiatric disorders.


Assuntos
Transtorno Bipolar , Transtorno Depressivo Maior , Esquizofrenia , Humanos , Adolescente , Transtorno Bipolar/metabolismo , Transtorno Depressivo Maior/metabolismo , Esquizofrenia/metabolismo , Metabolômica , Metaboloma
4.
Behav Brain Res ; 463: 114890, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38309372

RESUMO

Chronic stress is deemed a significant clinical contributor to depression. The use of animal models of chronic stress can fully reveal the complex pathological mechanisms and their changing trends in the pathogenesis of depression, which is crucial for both disease prevention and therapy. It is also unknown how various forms of stress differ in their impact on animal physiology and behavior. The nucleus accumbens (NAc), an essential brain area for the pathophysiology of depression, and its underlying neural mechanisms remain unclear. Here, we systematically compared transcriptional signatures in the NAc of four chronic stress models in rats: chronic unpredictable mild stress (CUMS), chronic social defeat stress (CSDS), learned helplessness (LH), chronic restraint stress (CRS). The majority of differentially expressed genes (DEGs) were unique to a single depression model, while the rank-rank hypergeometric overlap analysis showed that the CSDS and CRS models had the greatest overlap, and the CRS and CUMS models had the least. Then, we performed pathway analysis of the differential genes and found that the neuroactive ligand-receptor interaction pathway was significantly enriched not only in the LH, CRS and CSDS stress models, but also significantly enriched in stress genes that were also altered in at least two stress models. Finally, we found three hub genes (Dcx, Tnc and Wdfy4) by constructing co-expression networks for stress genes. In summary, our research has the potential to offer fresh insights into the molecular mechanisms underlying depression induced by different types of stress, highlighting both their similarities and differences. It may provide valuable clues for understanding the pathogenesis of depression.


Assuntos
Núcleo Accumbens , Estresse Psicológico , Ratos , Animais , Núcleo Accumbens/metabolismo , Estresse Psicológico/metabolismo , Encéfalo , Expressão Gênica , Modelos Animais de Doenças , Depressão/metabolismo , Comportamento Animal
5.
J Colloid Interface Sci ; 657: 538-549, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38070339

RESUMO

The exploitation of efficient, stable and cheap electrocatalyst for oxygen evolution reaction (OER) is very significant to the development of energy technology. In this study, Fe-based metal-organic frameworks (MIL-53(Fe)) self-supporting electrode with a 3D hierarchical open structure was developed through a semi-sacrificial strategy. The self-supporting electrode exhibits an excellent OER performance with an overpotential of 328 mV at 100 mA cm-2 in 1 M KOH, which is superior than that of IrO2 catalyst. Importantly, the optimized self-supporting electrode could operate at 100 mA cm-2 for 520 h without visible decrease in activity. It was also found that the structure of MIL-53(Fe) was in-situ self-reconstructed into oxyhydroxides during OER process. However, the 3D hierarchical open structure assembled with nano-microstructures kept well, which ensured the long-term stability of our self-supporting electrode for OER. Furthermore, density functional theory (DFT) calculations reveal that the FeOOH with rich oxygen vacancy transformed from MIL-53(Fe) plays a key role for the OER catalytic activity. And, the uninterrupted formation of oxygen vacancy during OER process ensures the continuous OER catalytic activity, which is the original source for the ultra-long stability of the self-supporting electrode toward OER. This work explores the way for the construction of efficient self-supporting oxygen electrodes based on MOFs.

6.
Biomed Pharmacother ; 170: 116098, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38154276

RESUMO

BACKGROUND: Inflammatory bowel diseases (IBD), such as severe colitis, are associated with the development of lung inflammation and tissue damage. Pueraria lobata (P. lobata) plays an essential role in controlling cytokines. However, the exact mechanism of the inflammation response is still unknown. PURPOSE: To investigate the effects of the P. lobata-derived exosomes-like nanovesicles (PLDENs) on colitis and their role in the lung inflammatory response. METHODS: In this study, we investigated the effects of PLDENs on the dextran sulfate sodium (DSS)-induced colitis and explored the mechanisms by forming the gut-lung axis. PLDENs were characterized by mass spectrometry-based proteomic analysis. RESULTS: The results showed that PLDENs had significant preventive effects in DSS-induced colitis and pathological changes in colons in a dose-dependent manner. Simultaneously, the treatment of PLDENs could effectively reduce inflammatory changes in the lung. PLDENs could selectively regulate the composition of gut microbiota. CONCLUSION: These data suggested that the treatment of PLDENs could 'attenuate DSS-induced colitis and lung inflammation, providing an efficacious supplement for reducing co-morbidities in IBD patients.


Assuntos
Colite , Exossomos , Doenças Inflamatórias Intestinais , Pneumonia , Pueraria , Humanos , Animais , Camundongos , Sulfato de Dextrana/toxicidade , Exossomos/patologia , Proteômica , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/patologia , Citocinas , Pneumonia/induzido quimicamente , Pneumonia/tratamento farmacológico , Macrófagos/patologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Inflamação/tratamento farmacológico , Colo/patologia
7.
BMC Psychiatry ; 23(1): 789, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37891522

RESUMO

BACKGROUND: Adolescent major depressive disorder (MDD) is a prevalent mental health problem with low treatment success rates. Whether fluoxetine or fluoxetine combined with cognitive-behavioural therapy (CBT) is the more effective initial treatment for adolescent MDD remains controversial, and few studies have investigated whether treatment switching or augmentation is preferred when the initial treatment is not working well. METHODS: We developed a multicentre open-label Sequential Multiple Assignment Randomized Trial (SMART) design, consisting of two phases lasting 8 weeks each. In phase 1 (at baseline), patients will be recruited and grouped in fluoxetine group or fluoxetine combined with CBT group by patient self-selection. In phase 2 (after 8 weeks of treatment), the nonresponders will be randomly assigned to six groups, in which participants will switch to sertraline, vortioxetine, or duloxetine or added aripiprazole, olanzapine, or lithium carbonate to fluoxetine. After the full 16 weeks of treatment, we will assess the long-term sustainability of the treatment effects by evaluating participants during their subsequent naturalistic treatment. The primary outcome will be the response rate, determined by the Children's Depression Rating Scale-Revised (CDRS-R). Secondary outcomes include the change in scores on the Beck Depression Inventory (BDI), the Screen for Child Anxiety-Related Emotional Disorders (SCARED) and the Safe Assessment. DISCUSSION: The results from this study will aid clinicians in making informed treatment selection decisions for adolescents with MDD. TRIAL REGISTRATION: This protocol was registered at ClinicalTrials.gov with Identifier: NCT05814640.


Assuntos
Terapia Cognitivo-Comportamental , Transtorno Depressivo Maior , Criança , Humanos , Adolescente , Fluoxetina/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Depressão/terapia , Terapia Combinada , Terapia Cognitivo-Comportamental/métodos , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
8.
ChemSusChem ; 16(24): e202300984, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-37670424

RESUMO

In alkaline seawater electrolysis, the oxygen evolution reaction (OER) is greatly suppressed by the occurrence of electrode corrosion due to the formation of hypochlorite. Herein, a catalyst consisting of MoC nanowires modified with NiFe alloy nanoparticles (NiFe/MoC) on nickel foam (NF) is prepared. The optimized catalyst can deliver a large current density of 500 mA cm-2 at a very low overpotential of 366 mV in alkaline seawater, respectively, outperforming commercial IrO2 . Remarkably, an electrolyzer assembled with NiFe/MoC/NF as the anode and NiMoN/NF as the cathode only requires 1.77 V to drive a current density of 500 mA cm-2 for alkaline seawater electrolysis, as well as excellent stability. Theory calculation indicates that the initial activity of NiFe/MoC is attributed to increased electrical conductivity and decreased energy barrier for OER due to the introduction of Fe. We find that the change of the catalyst in the composition occurred after the stability test; however, the reconstructed catalyst has an energy barrier close to that of the pristine one, which is responsible for its excellent long-term stability. Our findings provide an efficient way to construct high-performance OER catalysts for alkaline seawater splitting.

9.
Cell Commun Signal ; 21(1): 146, 2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37337219

RESUMO

BACKGROUND: Mesenchymal stem cells (MSCs) therapies are emerging as a promising approach to therapeutic regeneration. Therapeutic persistence and reduced functional stem cells following cell delivery remain critical hurdles for clinical investigation due to the senescence of freshly isolated cells and extensive in-vitro passage. METHODS: Cultured adipose-derived stem cells (ASCs) were derived from subcutaneous white adipose tissue isolated from mice fed a normal diet. We performed senescence-associated-ß-galactosidase (SA-ß-gal) staining, real-time PCR, and Westernblot to evaluate the levels related to cellular senescence markers. RESULTS: The mRNA expression levels of senescence markers were significantly increased in the later passage of ASCs. We show that light activation reduced the expression of senescent genes, and SA-ß-Gal in all cells at passages. Moreover, the light-activated ASCs-derived exosomes decrease the expression of senescence, and SA-ß-Gal in the later passage cells. We further investigated the photoreceptive effect of Opsin3 (Opn3) in light-activated ASCs. Deletion of Opn3 abolished the differences of light activation in reduced expression of senescent genes, increased Ca 2+ influx, and cAMP levels. CONCLUSIONS: ASCs can undergo cellular senescence in-vitro passage. Photomodulation might be better preserved over senescence and Opn3-dependent activation in aged ASCs. Light-activated ASCs-derived exosomes could be served as e a new protective paradigm for cellular senescence in-vitro passage. Video Abstract.


Assuntos
Tecido Adiposo , Senescência Celular , Animais , Camundongos , Diferenciação Celular , Tecido Adiposo/metabolismo , Proliferação de Células , Senescência Celular/genética , Células-Tronco , Células Cultivadas
10.
J Affect Disord ; 323: 659-666, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36493942

RESUMO

BACKGROUND: The etiology in major depressive disorder (MDD) has not been fully understood. Accumulating evidence suggests an association between altered intestinal and blood-brain barrier (BBB) permeability and psychiatric disorders, while its changes in adolescent MDD populations have been received less attention. In this study, our aim was to explore the differences in plasma levels of intestinal and blood-brain barrier permeability markers in adolescents with MDD compared with healthy controls (HCs). METHODS: We enrolled MDD (n = 50), and HCs (n = 40) with the age of 13-18 years old. The plasma level of zonulin, I-FABP, LPS, and claudin-5 were quantified. The Hamilton Depression Scale 17 items (HAMD-17) and Hamilton Anxiety Scale 14 items (HAMA-14) were used for symptom assessments. RESULTS: The plasma levels of zonulin, I-FABP, LPS, and claudin-5 in the MDD group were significantly higher than those in the HCs. Plasma I-FABP levels in MDD with moderate to severe anxiety were significantly higher than those in MDD without moderate to severe anxiety and HCs. In addition, these four biomarkers (alone or combined) can be used as diagnostic markers for MDD in adolescents. LIMITATIONS: The key limitation of this study is the blood measurements at a single time point with a relatively small sample size. CONCLUSIONS: These findings advance our understanding of the pathophysiology of intestinal barrier injury, bacterial translocation, and blood-brain barrier injury involved in adolescents with MDD.


Assuntos
Transtorno Depressivo Maior , Humanos , Adolescente , Transtorno Depressivo Maior/psicologia , Barreira Hematoencefálica , Claudina-5 , Lipopolissacarídeos , Biomarcadores , Permeabilidade
11.
Front Psychiatry ; 13: 929207, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35911235

RESUMO

Background: Children and adolescents are at a high risk of major depressive disorder (MDD) with known sex differences in epidemiology. However, there are currently no objective laboratory-based sex-specific biomarkers available to support the diagnoses of male and female patients with MDD. Methods: Here, a male set of 42 cases and 27 healthy controls (HCs) and a female set of 42 cases and 22 HCs were recruited. This study investigated the sex differences of plasma metabolite biomarkers in young patients with MDD by the application of ultra-high-performance liquid chromatography equipped with quadrupole time-of-flight mass spectrometry. Results: The metabolic profiles showed clear separations in both male and female sets. In total, this study identified 57 male-related and 53 female-related differential metabolites. Compared with HCs, both male and female subjects with MDD displayed four significantly altered pathways. Notably, biliverdin was selected as an independent diagnostic male-specific biomarker with an area under the receiver operating characteristic curve of 0.966, and phosphatidylcholine (10:0/14:1) was selected as a female-specific biomarker, achieving an area under the curve (AUC) of 0.957. Conclusion: This metabolomics study may aid in the development of a plasma-based test for the diagnosis of male and female children and adolescents with MDD, as well as give new insight into the pathophysiology of sex differences in children and adolescents with MDD.

12.
Micromachines (Basel) ; 13(8)2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36014222

RESUMO

The terahertz (THz) band is expected to become a key technology to meet the ever-increasing traffic demand for future 6G wireless communications, and a lot of efforts have been paid to develop its capacity. However, few studies have been concerned with the transmission security of such ultra-high-speed THz wireless links. In this paper, we comprehensively investigate the physical layer security (PLS) of a THz communication system in the presence of multiple eavesdroppers and beam scattering. The method of moments (MoM) was adopted so that the eavesdroppers' channel influenced by the PEC can be characterized. To establish a secure link, the traditional beamforming and artificial noise (AN) beamforming were considered as transmission schemes for comparison. For both schemes, we analyzed their secrecy transmission probability (STP) and ergodic secrecy capacity (ESC) in non-colluding and colluding cases, respectively. Numerical results show that eavesdroppers can indeed degrade the secrecy performance by changing the size or the location of the PEC, while the AN beamforming technique can be an effective candidate to counterbalance this adverse effect.

13.
J Colloid Interface Sci ; 619: 148-157, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35381483

RESUMO

Metal-organic frameworks (MOFs) with intrinsically porous structures and well-dispersed metal sites are promising candidates for the oxygen evolution reaction (OER). However, the practical applications of MOFs for OER are significantly constrained due to their poor charge transfer property and insufficient inherent activity. Herein, we utilized caffeic acid as a bridging agent to covalently bond FeNi-MOF with NiMoO4 in order to tune the charge transfer properties for efficient OER. The optimized organic-inorganic heterocatalyst demonstrates superior OER performance with a low overpotential of 256 mV at a current density of 10 mA cm-2 and long-term stability, outperforming the benchmark IrO2 catalyst and single counterparts. Both experimental and theoretical results indicate that electrons can be transferred from FeNi-MOF to NiMoO4 via a caffeic acid bridging agent, which improves not only the electrical conductivity but also the adsorption capacity of OH- intermediates on MOFs. Therefore, the enhanced OER activity of the heterocatalyst is attributed to the synergistic effects of the multi-components. This study paves the way for the rational design of MOFs-based heterostructures towards efficient electrocatalytic oxygen evolution.

14.
Psych J ; 11(2): 214-226, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34530499

RESUMO

The therapeutic effect of antidepressants has been demonstrated for anhedonia in patients with depression. However, antidepressants may cause side-effects, such as cardiovascular dysfunction. Although physical activity has minor side-effects, it may serve as an alternative for improving anhedonia and depression. We sought to investigate whether physical activity reduces the level of anhedonia in individuals with depression. Fifty-six university students with moderate depressive symptoms (Beck Depression Inventory total score > 16) were divided into three training groups: the Running Group (RG, n = 19), the Stretching Group (SG, n = 19), and the Control Group (n = 18). We employed the Monetary Incentive Delay (MID) task and the Temporal Experience of Pleasure Scale (TEPS) to evaluate hedonic capacity. All participants in the RG and SG received 8 weeks of jogging and stretching training, respectively. The RG experienced an increase in the level of arousal during anticipation of a future reward and recalled less negativity towards the loss condition. The SG exhibited enhanced scores on the Anticipatory and Consummatory Pleasure subscales of the TEPS after training. Moreover, in the RG, greater improvements in anticipatory arousal ratings for pleasure and remembered valence ratings for negative affect were associated with longer training duration, lower maximum heart rate, and higher consumed calories during training. To conclude, physical activity is effective in improving anticipatory anhedonia in individuals with depressive symptoms.


Assuntos
Anedonia , Depressão , Exercício Físico , Humanos , Motivação , Prazer
15.
Adv Mater ; 33(49): e2106781, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34623713

RESUMO

Metal-organic frameworks (MOFs) with intrinsically porous structures and well-dispersed metal sites are promising candidates for electrocatalysis; however, the catalytic efficiencies of most MOFs are significantly limited by their impertinent adsorption/desorption energy of intermediates formed during electrocatalysis and very low electrical conductivity. Herein, Co is introduced into conductive Cu-catecholate (Cu-CAT) nanorod arrays directly grown on a flexible carbon cloth for hydrogen evolution reaction (HER). Electrochemical results show that the Co-incorporated Cu-CAT nanorod arrays only need 52 and 143 mV overpotentials to drive a current density of 10 mA cm-2 in alkaline and neutral media for HER, respectively, much lower than most of the reported non-noble metal-based electrocatalysts and comparable to the benchmark Pt/C electrocatalyst. Density functional theory calculations show that the introduction of Co can optimize the adsorption energy of hydrogen (ΔGH* ) of Cu sites, almost close to that of Pt (111). Furthermore, the adsorption energy of water ( Δ E H 2 O ) of Co sites in the CuCo-CAT is significantly lower than that of Cu sites upon coupling Cu with Co, effectively accelerating the Volmer step in the HER process. The findings, synergistic effect of bimetals, open a new avenue for the rational design of highly efficient MOF-based electrocatalysts.

16.
Opt Express ; 28(22): 32386-32402, 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33114926

RESUMO

Continuous-variable quantum key distribution (CVQKD) in an indoor scenario can provide secure wireless access for practical short-distance communications with high rates. However, a suitable channel model for implementing the indoor CVQKD system has not been considered before. Here, we establish an indoor channel model to show the feasibility of CVQKD in terahertz (THz) band. We adopt both active and passive state preparation schemes to demonstrate the performance of the indoor CVQKD system involving multi-path propagation. We achieve the channel transmittance characterized by frequency, water-vapor density, antenna gain, reflection loss and the surrounding itself. The ray-tracing based numerical simulations show that the multi-path propagation can degrade the performance of the indoor CVQKD system. The maximum transmission distance is two meters at 410 GHz for both active and passive state preparations, and it can be extended to 35 and 20 meters respectively by using high gain antenna to combat the multi-path propagation.

17.
ACS Omega ; 5(13): 7369-7378, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32280878

RESUMO

In this work, coumarin derivatives (C) are used to enhance the fluorescence of graphene quantum dots (GQDs) by covalently linking the carboxyl groups on the edge of the GQD sheet. The as-synthesized coumarin-modified graphene quantum dots (C-GQDs) have a uniform particle size with an average diameter of 3.6 nm. Simultaneously, the C-GQDs have strong fluorescence emission, excellent photostability, and high fluorescence quantum yield. C-GQDs and CN- can form a C-GQDs+CN- system due to deprotonation and/or intermolecular interactions. The introduced hydroquinone (HQ) is oxidized to benzoquinone (BQ), and the interaction between BQ and the C-GQDs+CN- system could lead to fluorescence enhancement of C-GQDs. Meanwhile, the redox reaction between BQ and ascorbic acid (AA) can be used for quantitative detection of AA with CN- and HQ being used as substrates. Based on the above mechanism, C-GQDs are developed as a multicomponent detection and sensing platform, and the detection limits for CN-, HQ, and AA were 4.7, 2.2, and 2.2 nM, respectively. More importantly, satisfactory results were obtained when the platform was used to detect CN-, HQ, and AA in living cells and fresh fruits.

18.
Analyst ; 145(1): 213-222, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31742260

RESUMO

Accurate fabrication of fluorescence probes to efficiently monitor and detect H2S levels in the fields of foodstuffs and physiology is crucial. Herein, we report two isomeric phenanthro[9,10-d]imidazole benzene sulfonamide-derived fluorescence probes (PI-2-SA and PI-4-SA), both of which display remarkable responses toward H2S over other analytes. The spectral characteristics of the two probes were investigated and are discussed in detail. By comparison, PI-2-SA was specific, sensitive (the limit of detection was ca. 12.3 nM), rapid (within ≤3 min) and dynamic (the rate constant was 0.02 s-1). Significantly, PI-2-SA was proved to be effective in monitoring the shelf-time progress of egg samples in real time as well as in the imaging of exogenous and endogenous H2S in HeLa cells.


Assuntos
Ovos/análise , Corantes Fluorescentes/química , Sulfeto de Hidrogênio/análise , Imidazóis/química , Fenantrenos/química , Sulfonamidas/química , Animais , Galinhas , Patos , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Conservação de Alimentos/métodos , Células HeLa , Humanos , Sulfeto de Hidrogênio/metabolismo , Imidazóis/síntese química , Imidazóis/toxicidade , Isomerismo , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Fenantrenos/síntese química , Fenantrenos/toxicidade , Codorniz , Sulfonamidas/síntese química , Sulfonamidas/toxicidade
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