URANYL FLUORESCENCE INTENSITY AND DECAY

Background: Morin has many pharmacological functions including antioxidant, anticancer, anti-inflammatory, and antibacterial effects. It is commonly used in the treatment of antiviral infection, gastropathy, coronary heart disease and hepatitis B in clinic. However, researches have shown that morin is likely to show prooxidative effects on the cells when the amount of treatment is at high dose, leading to the decrease of intracellular ATP levels and the increase of necrosis process. Therefore, it is necessary to determine the concentration of morin in biologic samples. Method: Novel water-soluble and green nitrogen and sulfur co-doped carbon dots (NSCDs) were prepared by a microwave heating process with citric acid and L-cysteine. The fluorescence spectra were collected at an excitation wavelength of 350 nm when solutions of NSCDs were mixed with various concentrations of morin. Results: The as-prepared NSCDs were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The fluorescence intensity of NSCDs decreased significantly with the increase of morin concentration. The fluorescence intensity of NSCDs displayed a linear response to morin in the concentration 0.10-30 μM with a low detection limit of 56 nM. The proposed fluorescent probe was applied to analysis of morin in human body fluids with recoveries of 98.0-102%. Conclusion: NSCDs were prepared by a microwave heating process. The present analytical method is sensitive to morin. The quenching process between NSCDs and morin is attributed to the static quenching. In addition, the cellular toxicity on HeLa cells indicated that the as-prepared NSCDs fluorescent probe does not show obvious cytotoxicity in cell imaging. Our proposed method possibly opens up a rapid and nontoxic way for preparing heteroatom doped carbon dots with a broad application prospect.

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Membrane-potential-related fluorescence intensity indicates bacterial injury

Microbiological Research ◽

10.1016/s0944-5013(96)80036-x ◽

1996 ◽

Vol 151 (2) ◽

pp. 127-131 ◽

Cited By ~ 12

Author(s):

Susann Müller ◽

Norbert Loffhagen ◽

Thomas Bley ◽

Wolfgang Babel

Keyword(s):

Membrane Potential ◽

Fluorescence Intensity

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Recent Advances in Quenchbody, a Fluorescent Immunosensor

Sensors ◽

10.3390/s21041223 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1223

Author(s):

Jinhua Dong ◽

Hiroshi Ueda

Keyword(s):

Fluorescence Intensity ◽

Fluorescent Dyes ◽

Antibody Fragment ◽

Disease Diagnosis ◽

Disease Biomarkers ◽

Highly Sensitive ◽

Physiologically Active Substances ◽

New Type ◽

Antigen Antibody ◽

Active Substances

The detection of viruses, disease biomarkers, physiologically active substances, drugs, and chemicals is of great significance in many areas of our lives. Immunodetection technology is based on the specificity and affinity of antigen–antibody reactions. Compared with other analytical methods such as liquid chromatography coupled with mass spectrometry, which requires a large and expensive instrument, immunodetection has the advantages of simplicity and good selectivity and is thus widely used in disease diagnosis and food/environmental monitoring. Quenchbody (Q-body), a new type of fluorescent immunosensor, is an antibody fragment labeled with fluorescent dyes. When the Q-body binds to its antigen, the fluorescence intensity increases. The detection of antigens by changes in fluorescence intensity is simple, easy to operate, and highly sensitive. This review comprehensively discusses the principle, construction, application, and current progress related to Q-bodies.

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Effects of tacrolimus on autophagy protein LC3 in puromycin-damaged mouse podocytes

Journal of International Medical Research ◽

10.1177/0300060520971422 ◽

2020 ◽

Vol 48 (12) ◽

pp. 030006052097142

Author(s):

Xiao-qing Yang ◽

Sheng-you Yu ◽

Li Yu ◽

Lin Ge ◽

Yao Zhang ◽

...

Keyword(s):

Fluorescence Intensity ◽

Light Chain ◽

In Vitro Model ◽

Group Versus ◽

Podocyte Injury ◽

Apoptosis Rate ◽

Protein Levels ◽

Vitro Model ◽

Intercellular Connections

Objective To investigate the mechanism through which tacrolimus, often used to treat refractory nephropathy, protects against puromycin-induced podocyte injury. Methods An in vitro model of puromycin-induced podocyte injury was established by dividing podocytes into three groups: controls, puromycin only (PAN group), and puromycin plus tacrolimus (FK506 group). Podocyte morphology, number, apoptosis rate and microtubule associated protein 1 light chain 3 alpha ( LC3) expression were compared. Results Puromycin caused podocyte cell body shrinkage and loose intercellular connections, but podocyte morphology in the FK506 group was similar to controls. The apoptosis rate was lower in the FK506 group versus PAN group. The low level of LC3 mRNA observed in untreated podocytes was decreased by puromycin treatment; however, levels of LC3 mRNA were higher in the FK506 group versus PAN group. Although LC3-I and LC3-II protein levels were decreased by puromycin, levels in the FK506 group were higher than the PAN group. Fewer podocyte autophagosomes were observed in the control and FK506 groups versus the PAN group. Cytoplasmic LC3-related fluorescence intensity was stronger in control and FK506 podocytes versus the PAN group. Conclusions Tacrolimus inhibited puromycin-induced mouse podocyte damage by regulating LC3 expression and enhancing autophagy.

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Effectiveness of photon-initiated photoacoustic streaming in root canal models with different diameters or tapers

BMC Oral Health ◽

10.1186/s12903-021-01671-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Cheng Wen ◽

Yuanyuan Kong ◽

Jian Zhao ◽

Yang Li ◽

Ya Shen ◽

...

Keyword(s):

Fluorescence Intensity ◽

Root Canal ◽

Distilled Water ◽

Canal Irrigation ◽

Root Canals ◽

Atp Assay ◽

Root Canal Irrigation ◽

Average Fluorescence Intensity ◽

Different Diameters ◽

Average Fluorescence

Abstract Background This study aimed to compare the use of photon-initiated photoacoustic streaming (PIPS) and conventional needle irrigation (CNI) in conjunction with different concentrations of sodium hypochlorite (NaOCl) to remove Enterococcus faecalis (E. faecalis) suspended bacteria and biofilms from root canal systems with different diameters or tapers. Methods Artificial root canal samples (n = 480) were randomly divided into three groups (n = 160/group). The canals were prepared to fit file sizes #10/.02, #25/.02, or #25/.06. The size #10/.02 group was incubated for seven days. The size #25/.02 or #25/.06 group was incubated for 2 days. A stable biological model of E. faecalis infection was established. The root canals were washed with distilled water or with 1%, 2%, or 5.25% NaOCl combined with CNI or PIPS. Bacterial suspensions and biofilms were assessed using an ATP assay kit and fluorescence microscopy. Image-Pro Plus was used to analyse the average fluorescence intensity to determine the most suitable root canal irrigation solution. Results In the CNI and PIPS groups, the ATP value of the 5.25% NaOCl subgroup was the lowest, followed by that of the 2% and 1% NaOCl subgroups. The ATP value of the distilled water subgroup was the highest (P < 0.05). When the root canal taper was 0.02, the ATP value of the #10/.02 + PIPS group was significantly lower than that of the #25/.02 + CNI group (P < 0.05). The average fluorescence intensity of the #10/.02 + PIPS group was lower than that of the #25/.02 + CNI group (P < 0.05). When the apical diameter was #25, the ATP value of the 0.02 taper in the PIPS group was lower than that of the 0.06 taper in the CNI group (P < 0.05), and the average fluorescence intensity of the 0.02 taper + PIPS group was lower than that of the 0.06 taper + CNI group (P < 0.05). PIPS combined with 2% and 5.25% NaOCl effectively improved the long-term antibacterial effect after irrigation and re-culture for 6 h. Conclusions Compared with CNI, PIPS has greater ability to remove bacteria in root canals with a small preparation diameter and a small taper. PIPS with 2% and 5.25% NaOCl exhibited superior antibacterial and bacteriostatic effects.

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The quantitative analysis of the interaction of 1-anilinonaphthalene-8-sulfonate with liposomes: Fluorescence intensity and zeta-potential

Colloid & Polymer Science ◽

10.1007/bf01746688 ◽

1978 ◽

Vol 256 (1) ◽

pp. 31-36 ◽

Cited By ~ 18

Author(s):

N. Kamo ◽

T. Aiuchi ◽

K. Kurihara ◽

Y. Kobatake

Keyword(s):

Quantitative Analysis ◽

Zeta Potential ◽

Fluorescence Intensity

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Synthesis of Fluorescent Carbon Dots and Their Application in Ascorbic Acid Detection

Molecules ◽

10.3390/molecules26051246 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1246

Author(s):

Tengfei Wang ◽

Hui Luo ◽

Xu Jing ◽

Jiali Yang ◽

Meijun Huo ◽

...

Keyword(s):

Ascorbic Acid ◽

Fluorescence Intensity ◽

Carbon Dots ◽

Ph Dependence ◽

Scale Up ◽

Water Soluble ◽

Jujube Fruit ◽

Fluorescent Carbon Dots ◽

Fluorescent Carbon

Water-soluble fluorescent carbon dots (CDs) were synthesized by a hydrothermal method using citric acid as the carbon source and ethylenediamine as the nitrogen source. The repeated and scale-up synthetic experiments were carried out to explore the feasibility of macroscopic preparation of CDs. The CDs/Fe3+ composite was prepared by the interaction of the CDs solution and Fe3+ solution. The optical properties, pH dependence and stability behavior of CDs or the CDs/Fe3+ composite were studied by ultraviolet spectroscopy and fluorescence spectroscopy. Following the principles of fluorescence quenching after the addition of Fe3+ and then the fluorescence recovery after the addition of asorbic acid, the fluorescence intensity of the carbon dots was measured at λex = 360 nm, λem = 460 nm. The content of ascorbic acid was calculated by quantitative analysis of the changing fluorescence intensity. The CDs/Fe3+ composite was applied to the determination of different active molecules, and it was found that the composite had specific recognition of ascorbic acid and showed an excellent linear relationship in 5.0–350.0 μmol·L−1. Moreover, the detection limit was 3.11 μmol·L−1. Satisfactory results were achieved when the method was applied to the ascorbic acid determination in jujube fruit. The fluorescent carbon dots composites prepared in this study may have broad application prospects in a rapid, sensitive and trace determination of ascorbic acid content during food processing.

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