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1.
Int J Mol Sci ; 24(2)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36674921

RESUMO

Alcoholic liver damage is caused by long-term drinking, and it further develops into alcoholic liver diseases. In this study, we prepared a probiotic fermentation product of Grifola frondosa total active components (PFGF) by fermentation with Lactobacillus acidophilus, Lactobacillus rhamnosus, and Pediococcus acidilactici. After fermentation, the total sugar and protein content in the PFGF significantly decreased, while the lactic acid level and antioxidant activity of the PFGF increased. Afterward, we investigated the alleviating effect of PFGF on alcoholic liver injury in alcohol-fed mice. The results showed that the PFGF intervention reduced the necrosis of the liver cells, attenuated the inflammation of the liver and intestines, restored the liver function, increased the antioxidant factors of the liver, and maintained the cecum tissue barrier. Additionally, the results of the 16S rRNA sequencing analysis indicated that the PFGF intervention increased the relative abundance of beneficial bacteria, such as Lactobacillus, Ruminococcaceae, Parabacteroids, Parasutterella, and Alistipes, to attenuate intestinal inflammation. These results demonstrate that PFGF can potentially alleviate alcoholic liver damage by restoring the intestinal barrier and regulating the intestinal microflora.


Assuntos
Grifola , Hepatopatias Alcoólicas , Probióticos , Camundongos , Animais , Antioxidantes , RNA Ribossômico 16S/genética , Probióticos/uso terapêutico , Inflamação
2.
Environ Res ; 196: 110976, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33684414

RESUMO

OBJECTIVE: Rapid urbanization has led to reduced greenness in many areas, this has been linked to adverse health outcomes. The aim was to determine the association between residential greenness experienced during very early childhood with preschool myopia and astigmatism and to explore the potential mediating role of screen time on any associations. METHOD: Information regarding socio-demographic characteristics, home address, screen time during early childhood, and refraction data from vision screenings of 53,575 preschoolers from Longhua Child Cohort Study were collected via questionnaires. Residential greenness was calculated as the average of satellite-derived Normalized Difference Vegetation Index in buffers of 100, 250, and 500 m around each child's home address. Logistic and linear regression models were used to examine the relationships between residential greenness, screen time, and preschool myopia and astigmatism. RESULT: The mean (SD) age of the 53,575 preschoolers was 5.0 (0.7) years, and 24,849 (46.4%) were girls. A total of 1236 (2.3%) preschoolers had myopia and 5347 (10.0%) had astigmatism. In the adjusted model, a higher neighborhood greenness level within 100 m buffers around the home address was associated with decreased risk of myopia (adjusted odds ratios (AOR): 0.62, 95% confidence interval (CI): 0.38-0.99), and higher neighborhood greenness levels within 100, 250, and 500 m decreased the risk of astigmatism, and their AORs (95% CIs) were 0.55 (0.43-0.70) for 100 m, 0.59 (0.41-0.83) for 250 m, 0.61 (0.42-0.90) for 500 m, respectively. Greater screen time during early childhood increased the risk of myopia (AOR = 1.33) and astigmatism (AOR = 1.23). Reduction in screen time fully mediated the benefits of greater residential greenness on preschool myopia, but partially mediated that on preschool astigmatism (p < 0.05). CONCLUSION: Higher residential greenness reduces the risk of preschool myopia and astigmatism; the benefits of residential greenness were mediated through reduced daily screen time.


Assuntos
Astigmatismo , Miopia , Astigmatismo/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Masculino , Miopia/epidemiologia , Características de Residência , Instituições Acadêmicas
3.
Anal Chem ; 88(23): 11647-11653, 2016 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-27934126

RESUMO

A simple and novel method for evaluating antioxidants in complex biological fluids has been developed based on the interaction of dye-labeled single-strand DNA (ssDNA) and polydopamine (PDA). Due to the interaction between ssDNA and PDA, the fluorescence of dye-labeled ssDNA (e.g., FITC-ssDNA, as donor) can be quenched by PDA (as acceptor) to the fluorescence "off" state through Förster resonance energy transfer (FRET). However, in the presence of various antioxidants, such as glutathione (GSH), ascorbic acid (AA), cysteine (Cys), and homocysteine (Hcys), the spontaneous oxidative polymerization reaction from DA to PDA would be blocked, resulting in the freedom of FITC-ssDNA and leading to the fluorescence "on" state. The sensing system shows great sensitivity for the monitoring of antioxidants in a fluorescent "turn on" format. The new strategy also exhibits great selectivity and is free from the interferences of amino acids, metal ions and the biological species commonly existing in brain systems. Moreover, by combining the microdialysis technique, the present method has been successfully applied to monitor the dynamic changes of the striatum antioxidants in rat cerebrospinal microdialysates during the normal/ischemia/reperfusion process. This work establishes an effective platform for in vivo monitoring antioxidants in cerebral ischemia model, and promises new opportunities for the research of brain chemistry, neuroprotection, physiological, and pathological events.


Assuntos
Antioxidantes/análise , Córtex Cerebral/química , DNA/química , Corantes Fluorescentes/química , Indóis/química , Polímeros/química , Animais , Ácido Ascórbico/análise , Isquemia Encefálica , Cisteína/análise , Glutationa/análise , Homocisteína/análise , Ratos , Espectrometria de Fluorescência
4.
Analyst ; 141(8): 2347-50, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27010102

RESUMO

In this work, we prepared a type of thioflavin T (ThT)-doped lanthanide/nucleotide coordination polymer by the self-assembly of ThT, europium ions (Eu(3+)) and nucleotides (guanosine monophosphate, GMP) in aqueous solution (i.e. ThT/Eu/GMP). The Eu/GMP coordination polymers show excellent adaptive inclusion properties for ThT in a convenient one-step approach, which can readily enhance the fluorescence of ThT via the restricted effect. Moreover, the as-prepared hydrophilic ThT/Eu/GMP coordination polymers have the capability to act as a temperature-sensitive, visual and reversible sensor in aqueous solution under the irradiation of visible light. Our proposed design is cost-effective and simple to prepare without chemical modification or fluorescence labeling.

5.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 46(3): 399-402, 2015 May.
Artigo em Zh | MEDLINE | ID: mdl-26121861

RESUMO

OBJECTIVE: To observe the effect of nuclear factor erythroid 2-related factor 2 (Nrf2) agonist on the apoptosis of alveolar cell induced by hyperoxia and to explore whether Nrf2 activation could protect neonatal rats from hyperoxia induced lung injury. METHODS: 90 neonatal Sprague-Dawley rats were randomized into room air group (FiO2 =21%, N group), hyperoxia group (0 group) and Nrf2 group (n=30 each). Neonatal rats in the 0 group and Nrf2 group received saline 0. 2 mL and Nrf2 agonist 30 mg/kg respectively at the first and second day after birth, and were exposed in high concentration oxygen (95%) for 4 d. N group rats were fed in room air. The apoptotic index (AI) and Nrf2 expression of lung tissue were detected by TUNEL and immunohistochemistry staining respectively. RESULTS: Compared with 0 group (28. 8% ± 3. 0%), the AI of alveolar. cell was lower in N group (0. 7%±0. 6%) and Nrf2 group (7. 2% ± 0. 8%) (P<0. 01). The expression of Nrf2 was significantly higher in 0 group (926. 80 ± 130. 51) and Nrf2 group (1038. 40±151. 12) than that in N group (30. 03±9. 99) (P<0. 01). CONCLUSION: Nrf2 activation could reduce the alveolar cellular apoptosis and protect neonatal rats from hyperoxia induced lung injury.


Assuntos
Hiperóxia , Lesão Pulmonar , Pulmão/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/agonistas , Células Epiteliais Alveolares/citologia , Animais , Animais Recém-Nascidos , Apoptose , Pulmão/fisiopatologia , Ratos , Ratos Sprague-Dawley
6.
Analyst ; 139(22): 5682-5, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25272021

RESUMO

A simple and facile approach was developed for monitoring EcoRI endonuclease activity and inhibition, in which a hairpin-like DNA containing restriction cutting site for EcoRI endonuclease acts as the sensing element and Hoechst dyes as the signal indicator in a label-free format.


Assuntos
DNA/química , Endonucleases/metabolismo , Corantes Fluorescentes/química , Endonucleases/antagonistas & inibidores
7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 45(5): 777-9, 2014 Sep.
Artigo em Zh | MEDLINE | ID: mdl-25341338

RESUMO

OBJECTIVE: To investigate the effect of continuous exposure to hyperoxia on livers and changes in nuclear factor erythroid 2-related factor 2 (Nrf2) expression in hepatic tissues in neonatal rats. METHODS: 100 neonatal Sprague-Dawley rats were randomized divided into hyperoxia group (FiO = 95%, O group) and normal control group (FiOG2 = 21%, N group) immediately after birth. Hepatic apoptotic index and Nrf2 expression were detected by immunohistochemical methods on 4 d, 7 d, and 14 d. RESULTS: Rats with hyperoxia had higher levels of hepatic apoptotic index and Nrf2 expression compared with the controls (P < 0.01). The levels of hepatic apoptotic index and Nrf2 expression in rats with hyperoxia were higher on 7 d and 14 d than those on 4 d (P < 0.01). CONCLUSION: Continuous exposure to hyperoxia could result in hepatic damage to neonatal rats, with increased expression of Nrf2 as a mechanism of anti-oxidant.


Assuntos
Hiperóxia , Fígado/metabolismo , Fígado/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Animais Recém-Nascidos , Apoptose , Ratos , Ratos Sprague-Dawley
8.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 45(1): 39-42, 2014 Jan.
Artigo em Zh | MEDLINE | ID: mdl-24527579

RESUMO

OBJECTIVE: To investigate the protective effects of hydrogen on renal ischemic/reperfusion injury and its mechanism in rats. METHODS: Eighteen adult male Sprague-Dawley rats were used and allocated into sham-operated group (Sham group), ischemic reperfusion group (I/R group) and hydrogen treated group (H2 group) randomly. Ischemic/reperfusion of the left renal pedicles following a right nephrectomy was investigated in I/R group. In the Sham group, the rats were subjected to identical surgical procedure without occlusion of left renal pedicles. In the H2 group, inhalation of the 2.5% hydrogen was initiated 10 min before reperfusion and last for 130 min till the end of the 120-min reperfusion. Plasma level of usea nitrogen (BUN), creatinine (Cr), maiondiaidehyde (MDA), the score of histopathological examination of left kidney were evaluated 24 h after operation in all subjects. RESULTS: Ischemia-reperfusion injury rat model was established successfully. Inhalation of hydrogen (2.5%) markedly reduced the level of serum BUN, CREA and MDA (P < 0.05). The histopathological outcome in the H2 group was significantly improved, compared to the I/R group (P < 0.05). CONCLUSION: Inhalation of hydrogen could attenuate renal ischemic/reperfusion injury in rats by decreasing the content of MDA.


Assuntos
Hidrogênio/uso terapêutico , Rim/patologia , Traumatismo por Reperfusão/terapia , Animais , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Masculino , Malondialdeído/sangue , Nefrectomia , Ratos , Ratos Sprague-Dawley
9.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 45(6): 937-40, 2014 Nov.
Artigo em Zh | MEDLINE | ID: mdl-25571719

RESUMO

OBJECTIVE: To investigate the changes of lung cell apoptosis and the expression of notch signaling in the lung of neonatal rats exposed to hyperoxia and to explore the internal relationship between notch1 and hyperoxia-induced lung injury. METHODS: 120 neonatal Sprague-Dawley rats of 22-day gestational age were randomized continually exposed to hyperoxia (FiO2 = 95%, hyperoxia group) or room air (FiO2 21%, air group) 30 minutes after birth. The notch signaling expression in the lung were detected by immunohistochemical methods respectively at 4, 7, 14 days after inhale hyperoxia or air. At the same time, pathological changes in the different groups were also observed with light microscope and lung cell apoptosis was determined quantitatively by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) methods. RESULTS: The biopsy test showed lung injury in hyperoxia group. The amount of apoptosis cell in hyperoxia was higer than that in the control group, and increased with the prolongation of hyperoxia supply. Positive staining for North1 in hyperoxia group was much lower than that in control group at every time point (P<0. 01, P<0. 05). CONCLUSION: Continually hyperoxic exposure might resulted in the lung injury and development of arrest. The abnormal expression of notch signaling might contributed to the pathogenesis of hyperoxia-induced lung injury in newborn rats.


Assuntos
Apoptose , Hiperóxia/patologia , Pulmão/citologia , Receptor Notch1/metabolismo , Transdução de Sinais , Animais , Animais Recém-Nascidos , Pulmão/metabolismo , Pulmão/patologia , Lesão Pulmonar , Ratos , Ratos Sprague-Dawley
10.
Anal Chem ; 85(23): 11665-74, 2013 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-24215505

RESUMO

In this study, we have developed a novel strategy to highly sensitize the luminescence of terbium(III) (Tb(3+)) using a designed guanine/thymine-rich DNA (5'-[G3T]5-3') as an antenna ligand, in which [G3T]5 improved the luminescence of Tb(3+) by 3 orders of magnitude due to energy transfer from nucleic acids to Tb(3+) (i.e., antenna effect). Furthermore, label-free probes for the luminescent detection of biothiols, Ag(+), and sequence-specific DNA in an inexpensive, simple, and mix-and-read format are presented based on the [G3T]5-sensitized luminescence of Tb(3+) (GTSLT). The long luminescence lifetime of the probes readily enables time-resolved luminescence (TRL) experiments. Hg(2+) can efficiently quench the luminescence of Tb(3+) sensitized by [G3T]5 (Tb(3+)/[G3T]5); however, biothiols are readily applicable to selectively grab Hg(2+) for restoration of the luminescence of Tb(3+)/[G3T]5 initially quenched by Hg(2+), which can be used for "turn on" detection of biothiols. With the use of cytosine (C)-rich oligonucleotide c[G3T]5 complementary to [G3T]5, the formed [G3T]5/c[G3T]5 duplex cannot sensitize the luminescence of Tb(3+). However, in the presence of Ag(+), Ag(+) can combine the C base of c[G3T]5 to form C-Ag(+)-C complexes, leading to the split of the [G3T]5/c[G3T]5 duplex and then release of [G3T]5. The released [G3T]5 acts as an antenna ligand for sensitizing the luminescence of Tb(3+). Therefore, the Tb(3+)/[G3T]5/c[G3T]5 probe can be applied to detect Ag(+) in a "turn on" format. Moreover, recognition of target DNA via hybridization to a molecular beacon (MB)-like probe (MB-[G3T]5) can unfold the MB-[G3T]5 to release the [G3T]5 for sensitizing the luminescence of Tb(3+), producing a detectable signal directly proportional to the amount of target DNA of interest. This allows the development of a fascinating label-free MB probe for DNA sensing based on the luminescence of Tb(3+). Results and methods reported here suggest that a guanine/thymine-rich DNA-sensitized luminescence probe of Tb(3+) represents a new opportunity for versatile background-free biosensing applications.


Assuntos
DNA/química , Guanina/química , Substâncias Luminescentes/química , Medições Luminescentes/métodos , Térbio/química , Timina/química , Humanos , Fatores de Tempo
11.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 43(1): 38-40, 2012 Jan.
Artigo em Zh | MEDLINE | ID: mdl-22455128

RESUMO

OBJECTIVE: To investigate the protective effects of morphine postconditioning on the renal hypoxic/ reoxygenation injury in rabbit and the mechanisms involved. METHODS: Hypoxic/reoxygenation injury was induced with inhalation 8% O2 3 hours followed by breathing in air 48 hours. Thirty male white New Zealand rabbits were randomly divided into 3 groups: normal control group, hypoxic/reoxgenation group (H/R group) and morphine hypoxic postconditioning group (MO+H/R group). Animals in H/R and MO+H/R group received 5 mL of saline or morphine 3 mg/kg respectively before induction reoxygenation. The levels of serum creatinine (SCr) and blood urea nitrogen (BUN) were detected respectively at 48 hour after bypoxic and reoxgenation happened. Pathological changes in the different groups were also evaluated by light microscope. Renal apoptosis was determined quantitatively by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)methods. Result The SCr and BUN in H/R group and MO+ H/R group were much higher respectively when compared with those in the N group. The SCr and BUN in MO+H/R group were much higher compared with those in the H/R group. The renal pathological changes were more severe in the H/R group than that of MO+H/R group. Apoptosis phenomenon was lower in MO+H/R group than H/R group (P < 0.05). CONCLUSION: Morphine postconditioning can protect rabbit against acute renal hypoxic/reoxygenation injury by reducing renal apoptosis.


Assuntos
Pós-Condicionamento Isquêmico/métodos , Rim/irrigação sanguínea , Rim/patologia , Morfina/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Hipóxia/complicações , Rim/metabolismo , Masculino , Morfina/uso terapêutico , Coelhos , Distribuição Aleatória , Superóxido Dismutase/metabolismo
12.
Front Public Health ; 9: 607911, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33748061

RESUMO

Evidence regarding screen use and outdoor activity during very early childhood (i. e., from aged 1 to 3 years) and their potential combined links to the later preschool myopia is limited. This information is needed to release effective public health messages and propose intervention strategies against preschool myopia. We collected information regarding very early childhood screen use, outdoor activity and the kindergartens vision screenings of 26,611 preschoolers from Longhua Child Cohort Study by questionnaires. Logistic regression models were used to examine the associations between reported outdoor activity, screen use from 1 to 3 years of age, and preschool myopia. Throughout very early childhood, from 1 to 3 years, the proportion of children exposed to screens increased (from 35.8 to 68.4%, p < 0.001), whereas the proportion of children who went outdoors ≥7 times/week (67.4-62.1%, p < 0.001) and who went outdoors for ≥60 min/time (53.3-38.0%, p < 0.001) declined. Exposure to fixed screen devices [adjusted odds ratio (AOR) = 2.66, 95% confidence interval (CI) = 2.09-3.44], mobile screen devices (AOR = 2.76, 95% CI = 2.15-3.58), and limited outdoor activity (AOR = 1.87, 95% CI = 1.42-2.51) during early childhood were associated with preschool myopia. Among children whose parents were myopic, the interactions between outdoor activity and fixed or mobile screen use on later preschool myopia were significant; the ORs and 95% CI were 3.34 (1.19-9.98) and 3.04 (1.06-9.21), respectively. Our findings suggest the possibility that the impact of screen exposure during early childhood on preschool myopia could be diminished by outdoor activity for children whose parents have myopia.


Assuntos
Atividades de Lazer , Miopia , Criança , Pré-Escolar , Estudos de Coortes , Humanos , Lactente , Miopia/diagnóstico , Razão de Chances , Instituições Acadêmicas
13.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 41(3): 412-4, 2010 May.
Artigo em Zh | MEDLINE | ID: mdl-20629310

RESUMO

OBJECTIVE: To investigate the protective effect of morphine hypoxic preconditioning on hepatic hypoxic/reoxygenation injury in rabbits and the mechanisms involved. METHODS: Hypoxic/reoxygenation injury was induced with inhalation of 8% O2 for 3 hours followed by air for 3 hours. Thirty male white New Zealand rabbits were randomly divided into 3 groups: normal control group (N group), hypoxic/reoxgenation group (H/R group) and morphine hypoxic preconditioning group (MO + H/R group). Animals in the H/R and MO + H/R groups received 5 mL of saline or 3 mg/kg of morphine respectively before the induction of hypoxic injury. Hepatic apoptosis was determined quantitatively by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) methods. The activity of superoxide dismulase (SOD) in liver tissues was measured at the end of reoxgygenation. RESULTS: A large number of TUNEL positive cells [(9.50 +/- 1.00)%] were observed in hepatic tissues of rabbits in the H/R group. The administration of morphine exerted a significant anti-apoptotic effect, as evidenced by reduced TUNEL-positive staining [(2.20 +/- 0.40)%, P < 0.05 vs. H/R group]. Compared with the H/R group, treatment with morphine increased SOD activity significantly [(85.57 +/- 19.37) vs. (48.35 +/- 15.84), P < 0.05)]. CONCLUSION: Morphine hypoxic preconditioning can protect rabbits against acute hepatic hypoxic/ reoxygenation injury by increasing SOD activity and reducing hepatic apoptosis.


Assuntos
Precondicionamento Isquêmico/métodos , Fígado/irrigação sanguínea , Morfina/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Coelhos , Distribuição Aleatória , Superóxido Dismutase/metabolismo
15.
Talanta ; 150: 615-21, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26838450

RESUMO

In this work, we presented a simple, label-free and rapid-responsive fluorescence assay for iodide (I(-)) detection based on "molecular beacon (MB)"-hosted thioflavin T (ThT), achieving a limit of detection as low as 158 nM. The proposed method exhibited very good selectivity to I(-) ions over other anions interference due to the strong binding force between I(-) ions with Hg(2+). Upon the addition of I(-) ions, it would capture Hg(2+) from a T-Hg(2+)-T complex belonging to the MB-like DNA hairpin structure, which eventually quenched the initial fluorescence as output. In addition, it was successfully applied for operation of an integrated DNA logic gate system and to the determination of I(-) in real samples such as human urine.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Corantes Fluorescentes/química , Iodetos/urina , Mercúrio/química , Espectrometria de Fluorescência/métodos , Tiazóis/química , Benzotiazóis , Humanos
18.
Chem Commun (Camb) ; 49(21): 2133-5, 2013 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-23389052

RESUMO

A molecular beacon (MB)-like DNA hairpin biosensor based on the reversible directing fluorescence of Hoechst dyes was developed for fluorescent detection of Hg(2+) and biothiols and furthermore for logic operation.


Assuntos
Técnicas Biossensoriais , Corantes Fluorescentes/química , Mercúrio/análise , Espectrometria de Fluorescência , Compostos de Sulfidrila/química , Dicroísmo Circular , Cisteína/química , DNA/química , Sequências Repetidas Invertidas
19.
ACS Appl Mater Interfaces ; 5(3): 473-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23298262

RESUMO

A label-free assay is reported in this work for the detection of DNA with enhanced sensitivity using complex DNA structures (DNA tetrahedrons) based on the biolayer interferometry. The DNA tetrahedrons help to amplify the optical signals of the biolayer interferometry, thus improving the detection limit of DNA by about 100-fold. We further demonstrated that this method could be expanded to ATP detection by taking advantage of the target-dependent adaptability of aptamers. It appears to us that this new label-free assay promises new opportunities for developing novel biolayer interferometry assays.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Interferometria/métodos , Conformação de Ácido Nucleico
20.
Talanta ; 117: 399-404, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24209359

RESUMO

Most of the copper (II) fluorescent probes are based on the measurement of fluorescence at a single wavelength, which may be influenced by variations in the sample environment. To the end, the ratiometric fluorescent measurement, which involves the simultaneous measurement of two fluorescence signals at different wavelengths followed by calculation of their intensity ratio, can effectively eliminate the adverse effects on fluorescence signals and give greater precision to the data analysis relative to single-channel detection. In this work, we prepared novel luminescent gold nanoclusters (AuNCs) utilizing vitamin B2 (riboflavin) as stabilizer by a simple, rapid and one-pot green (low-toxicity materials use) procedure. The as-prepared riboflavin-AuNCs (Ri-AuNCs) solution can be luminescent exhibiting two fluorescence emission peaks at 530 nm and around 840 nm with excitation at 375 nm, however, in the presence of Cu(2+), the fluorescence of the Ri-AuNCs was found to be quenched at around 840 nm and enhanced at 530 nm by Cu(2+). The resultant ratiometric fluorescent response can provide a novel sensory probe for the determination of Cu(2+). The present probe had excellent selectivity in the presence of several cations. The probe revealed a detection limit of 0.9 µM of Cu(2+). Moreover, our proposed probe can reversibly switch between the "on" and "off" states through the addition of Cu(2+) and EDTA, which is reusable in practical application. Results and method reported here provide a unique strategy for performance of ratiometric assays demonstrated with a AuNCs-based fluorescent probe, which expands the application of AuNCs.


Assuntos
Cobre/análise , Água Potável/química , Corantes Fluorescentes/química , Ouro/química , Nanopartículas Metálicas/química , Riboflavina/química , Cátions Bivalentes , Ácido Edético/química , Reutilização de Equipamento , Humanos , Limite de Detecção , Espectrometria de Fluorescência
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