Double emission fluorescence probes based on unconventional fluorescent molecules and fluorescein isothiocyanate for ClO− and Cu2+ detection

This paper presents the synthesis of silver nanoparticles (AgNPs) functionalized with fluorescent molecules, in particular with xanthene-based dyes, i.e., fluorescein isothiocyanate (FITC, λmax = 485 nm) and rhodamine B isothiocyanate (RITC, λmax = 555 nm). An in-depth characterization of the particle–dye systems, i.e., AgNPs–RITC and AgNPs–FITC, is presented to evaluate their chemical structure and optical properties due to the interaction between their plasmonic and absorption properties. UV–Vis spectroscopy and the dynamic light scattering (DLS) measurements confirmed the nanosize of the AgNPs–RITC and AgNPs–FITC. Synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS) was used to study the chemical surface functionalization by structural characterization, confirming/examining the isothiocyanate–metal interaction. For AgNPs–RITC, in which the plasmonic and fluorescence peak are not superimposed, the transient dynamics of the dye fluorescence were also studied. Transient absorption measurements showed that by exciting the AgNPs–RITC sample at a wavelength corresponding to the AgNP plasmon resonance, it was possible to preferentially excite the RITC dye molecules attached to the surface of the NPs with respect to the free dye molecules in the solution. These results demonstrate how, by combining plasmonics and fluorescence, these AgNPs can be used as promising systems in biosensing and imaging applications.

Download Full-text

Physiological Effects of Nonimmune Platelet Associated Immunoglobulin G

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650123 ◽

1981 ◽

Vol 45 (01) ◽

pp. 027-033 ◽

Cited By ~ 10

Author(s):

K Sugiura ◽

M Steiner ◽

M Baldini

Keyword(s):

Shape Change ◽

Fluorescein Isothiocyanate ◽

Recovery Phase ◽

Human Platelets ◽

Serotonin Release ◽

Platelet Volume ◽

Igg Antibody ◽

Heterologous Antiserum ◽

Igg Binding ◽

Series Of Experiments

SummaryThe function of nonimmune IgG associated with platelets is unknown. In a series of experiments we have investigated this problem, relating amount of platelet-associated IgG (PAIgG) to platelet volume, serotonin release, adherence of platelets to monocytes and platelet senescence. Most of these studies were performed with human platelets. Platelets freed of preexisting PAIgG by incubation at 22° C were incubated with IgG in a series of concentrations ranging from 0.4 — 27.0 X10-6 M. The IgG preparations used were demonstrably free of aggregated forms of the protein. The amount of PAIgG bound to platelets was determined by the use of fluorescein isothiocyanate-conjugated anti-IgG antibody (F-anti-IgG antibody) which was quantified in a fluorospectrophotometer. Newly bound IgG was assayed similarly by the use of F-IgG. A dose-dependent increase in platelet volume was associated with the binding of nonimmune IgG by platelets. The process which leveled off at an IgG concentration of 1.2 —1.5 X10-5 M was almost fully reversible and was not due to platelet shape change or aggregation. Release of serotonin from IgG-treated platelets was relatively small but to the extent that it occurred was positively related to the IgG concentration to which platelets were exposed. Adherence to autologous monocytes studied quantitatively by the use of formaldehyde-fixed cells was also positively related to the amount of IgG on the platelets. Normal or IgG-defident serum had a potent inhibitory (noncompetitive) action on the binding of F-IgG and F-anti-human IgG antibody to human platelets. Cohorts of platelets prepared in rabbits during the recovery phase of immunological thrombocytopenia induced by injection of heterologous antiserum, showed an age-dependent increase of PAIgG and of IgG binding. These results suggest that PAIgG plays a role in the clearance of senescent platelets.

Download Full-text

Interspecific variation of zona pellucida glycoconjugates in several species of marsupial

Reproduction ◽

10.1530/reprod/119.1.111 ◽

2000 ◽

pp. 111-120 ◽

Cited By ~ 5

Author(s):

JA Chapman ◽

OW Wiebkin ◽

WG Breed

Keyword(s):

Glycine Max ◽

Sialic Acid ◽

Zona Pellucida ◽

Fluorescein Isothiocyanate ◽

Interspecific Variation ◽

Lectin Histochemistry ◽

Sialic Acids ◽

Arachis Hypogea ◽

Marsupial Species ◽

Similar Intensity

The zona pellucida glycoconjugate content of several marsupial species was investigated using differential lectin histochemistry. Ovaries from fat-tailed dunnarts, a southern brown bandicoot, grey short-tailed opossums, brushtail possums, ringtail possums, koalas and eastern grey kangaroos were fixed, embedded in paraffin wax, sectioned and stained with ten fluorescein isothiocyanate-conjugated lectins. Sections were also incubated with either neuraminidase or saponified, respectively, before incubation with the lectins to identify saccharide residues masked by sialic acids or O-acetyl groups on sialic acids. The zonae pellucidae surrounding the oocytes of the marsupials demonstrated interspecific variation in glycoconjugate content, with mannose-containing glycoconjugates exhibiting the greatest variation. Some of the zona pellucida glycoconjugates of all species, except those of the opossums, were masked by sialic acid with an increase in fluorescence with lectins from Arachis hypogea (PNA), and Glycine max (SBA), after desialylation. The disaccharide beta-galactose(1-4)N-acetyl-D-glucosamine appeared to be conformationally masked by O-acetyl groups of sialic acids in the zonae pellucidae of all species, with an increase in fluorescence with the lectin from Erythrina cristagalli (ECA), after saponification. Similar intensity and localization of beta-(1-4)-N-acetyl-D-glucosamine, as shown by staining of the lectin from Triticum vulgaris (WGA), to the inner and outer regions of the zona pellucida, were found to those reported in eutherian species. WGA fluorescence became uniform throughout the zonae pellucidae after saponification, indicating differential O-acetylation of sialic acids on the internal compartment of the zonae pellucidae.

Download Full-text

Probing the Structural Features and the Micro-heterogeneity of Various Deep Eutectic Solvents and their Water Dilutions by the Photophysical Behaviour of Two Fluorophores

10.26434/chemrxiv.13395683.v1 ◽

2020 ◽

Author(s):

Matteo Tiecco ◽

Irene Di Guida ◽

Pier Luigi Gentili ◽

Raimondo Germani ◽

Carmela Bonaccorso ◽

...

Keyword(s):

Hydrogen Bond ◽

Transient Absorption ◽

Photophysical Properties ◽

Deep Eutectic Solvents ◽

Structural Features ◽

Solvation Dynamics ◽

Structured Systems ◽

Reduced Viscosity ◽

Bond Network ◽

Fluorescent Molecules

<div><div><div><p>The structural features of a series of diverse Deep Eutectic Solvents (DESs) have been investigated and characterized by means of two fluorescent probes. The spectral and photophysical properties of the latter are strictly dependent on the experienced environment, so that they can provide insights into the polarity, viscosity, hydrogen-bond network, and micro-heterogeneity of the various DESs.</p><p>In fact, the investigated DESs exhibit a variety of properties with regards to their hydrophilicity, acidity, and hydrogen-bond ability, and these details were deeply probed by the two fluorescent molecules. The effect of the addition of water, which is a key strategy for tuning the properties of these structured systems, was also tested. In particular, the excited state dynamics of the probes, measured by femtosecond-resolved transient absorption, proved instrumental in understanding the changes in the structural properties of the DESs, namely reduced viscosity and enhanced heterogeneity, as the water percentage increases. Differences between the various DESs in terms of both local microheterogeneity and bulk viscosity also emerged from the peculiar multi-exponential solvation dynamics undergone by the excited states of the probes.</p></div></div></div>

Download Full-text

Probing the Structural Features and the Micro-heterogeneity of Various Deep Eutectic Solvents and their Water Dilutions by the Photophysical Behaviour of Two Fluorophores

10.26434/chemrxiv.13395683 ◽

2020 ◽

Author(s):

Matteo Tiecco ◽

Irene Di Guida ◽

Pier Luigi Gentili ◽

Raimondo Germani ◽

Carmela Bonaccorso ◽

...

Keyword(s):

Hydrogen Bond ◽

Transient Absorption ◽

Photophysical Properties ◽

Deep Eutectic Solvents ◽

Structural Features ◽

Solvation Dynamics ◽

Structured Systems ◽

Reduced Viscosity ◽

Bond Network ◽

Fluorescent Molecules

<div><div><div><p>The structural features of a series of diverse Deep Eutectic Solvents (DESs) have been investigated and characterized by means of two fluorescent probes. The spectral and photophysical properties of the latter are strictly dependent on the experienced environment, so that they can provide insights into the polarity, viscosity, hydrogen-bond network, and micro-heterogeneity of the various DESs.</p><p>In fact, the investigated DESs exhibit a variety of properties with regards to their hydrophilicity, acidity, and hydrogen-bond ability, and these details were deeply probed by the two fluorescent molecules. The effect of the addition of water, which is a key strategy for tuning the properties of these structured systems, was also tested. In particular, the excited state dynamics of the probes, measured by femtosecond-resolved transient absorption, proved instrumental in understanding the changes in the structural properties of the DESs, namely reduced viscosity and enhanced heterogeneity, as the water percentage increases. Differences between the various DESs in terms of both local microheterogeneity and bulk viscosity also emerged from the peculiar multi-exponential solvation dynamics undergone by the excited states of the probes.</p></div></div></div>

Download Full-text

Lanthanide-doped Fluorescence Probes for NIR-Ⅱ Fluorescence Imaging

Chinese Journal of Luminescence ◽

10.37188/cjl.20200340 ◽

2020 ◽

Vol 41 (12) ◽

pp. 1460-1478

Author(s):

Song-tao ZHANG ◽

◽

Ying-hui WANG ◽

Hong-jie ZHANG ◽

◽

...

Keyword(s):

Fluorescence Imaging ◽

Fluorescence Probes

Download Full-text

Recent Progress in Chemosensors Using Aldehyde-bearing Fluorophores for the Detection of Specific Analytes and their Bioimaging

Current Medicinal Chemistry ◽

10.2174/0929867325666180117095528 ◽

2019 ◽

Vol 26 (21) ◽

pp. 4003-4028 ◽

Cited By ~ 1

Author(s):

Fangjun Huo ◽

Yaqiong Zhang ◽

Caixia Yin

Keyword(s):

Biomedical Research ◽

Nucleophilic Addition ◽

Recent Progress ◽

Biological Imaging ◽

Tissue Imaging ◽

Fluorescence Probes ◽

Biological Applications ◽

Convenient Procedure ◽

Nucleophilic Mechanism

In recent years, aldehyde-appended fluorescence probes have attracted increasing attention. Fluorescent biological imaging includes many modern applications for cell and tissue imaging in biomedical research. Meanwhile, the nucleophilic mechanism is a very simple and convenient procedure for the preparation of aldehyde-sensing probes. This tutorial review focuses on aldehyde-bearing chemosensors based on nucleophilic addition mechanism with biological applications.

Download Full-text

Specific and rapid reverse assaying protocol for detection and antimicrobial susceptibility testing of Pseudomonas aeruginosa based on dual molecular recognition

Scientific Reports ◽

10.1038/s41598-021-90619-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yong He ◽

Hang Zhao ◽

Yuanwen Liu ◽

He Zhou

Keyword(s):

Pseudomonas Aeruginosa ◽

Antimicrobial Susceptibility ◽

Magnetic Particles ◽

Susceptibility Testing ◽

Fluorescein Isothiocyanate ◽

High Specificity ◽

Antimicrobial Susceptibility Testing ◽

Tail Fiber ◽

Isolation And Identification ◽

Magainin Ii

AbstractThe worldwide emergence and spread of antimicrobial resistance is accelerated by irrational administration and use of empiric antibiotics. A key point to the crisis is a lack of rapid diagnostic protocols for antimicrobial susceptibility testing (AST), which is crucial for a timely and rational antibiotic prescription. Here, a recombinant bacteriophage tail fiber protein (TFP) was functionalized on magnetic particles to specifically capture Pseudomonas aeruginosa, while fluorescein isothiocyanate-labeled-magainin II was utilized as the indicator. For solving the magnetic particles’ blocking effects, a reverse assaying protocol based on TFP recognition was developed to investigate the feasibility of detection and AST of P. aeruginosa. P. aeruginosa can be rapidly, sensitively and specifically detected within 1.5 h with a linear range of 1.0 × 102 to 1.0 × 106 colony forming units (CFU)⋅mL−1 and a detection limit of 3.3 × 10 CFU⋅mL−1. Subsequently, AST results, which were consistent with broth dilution results, can be obtained within 3.5 h. Due to the high specificity of the TFP, AST can actually be conducted without the need for bacterial isolation and identification. Based on the proof-of-principle work, the detection and AST of other pathogens can be extended by expressing the TFPs of their bacteriophages.

Download Full-text

Spray-Dried Plasma Improves Body Weight, Intestinal Barrier Function, and Tibia Strength during Experimental Constant Heat Stress Conditions

Animals ◽

10.3390/ani11082213 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2213

Author(s):

Jared Ruff ◽

Thaina L. Barros ◽

Joy Campbell ◽

Ricardo González-Esquerra ◽

Christine N. Vuong ◽

...

Keyword(s):

Heat Stress ◽

Intestinal Barrier ◽

Fluorescein Isothiocyanate ◽

Serum Levels ◽

Negative Control ◽

Intestinal Barrier Function ◽

Negative Consequences ◽

Fluorescein Isothiocyanate Dextran ◽

Prolonged Heat ◽

Spray Dried

The aim of this study was to see how spray-dried plasma (SDP) supplementation affected broiler chicken performance, intestinal permeability, and bone strength during persistent heat stress. One-day-old chicks (n = 480) were randomly assigned into twelve environmental corrals; four thermoneutral (TN-negative control, maintained at 24 °C from d 21–42); four heat stress (HS, exposed to 35 °C from d 21–42); and four heat stress treated with 2% SDP in the feed until d 28 followed by 1% SDP until d 42 (HS-SDP). The performance and serum levels of fluorescein isothiocyanate-dextran (FITC-d) were evaluated at d 21, 28, 35, and 42. The tibias strength was evaluated on d 21 and 42. The increment in chicken temperature (p < 0.05) was observed two h following the increase in environmental temperature in both HS groups and was associated with decreased performance parameters compared with the TN group. At d 42 of age, the chickens exposed to HS had an impaired gut permeability and decreased tibia strength compared to the TN group (p < 0.05). However, partially feeding SDP mitigated these adverse effects significantly. These findings imply that using SDP strategically during stressful times, such as prolonged heat stress, may help mitigate its negative consequences.

Download Full-text

Delivery of Foreign Materials into Adherent Cells by Gold Nanoparticle-Mediated Photoporation

Membranes ◽

10.3390/membranes11080550 ◽

2021 ◽

Vol 11 (8) ◽

pp. 550

Author(s):

Xiaofan Du ◽

Jing Wang ◽

Lan Chen ◽

Zhenxi Zhang ◽

Cuiping Yao

Keyword(s):

Fluorescein Isothiocyanate ◽

Adherent Cells ◽

Thermal Dynamics ◽

Cervical Cell ◽

Nanosecond Pulse Laser ◽

Fluorescein Isothiocyanate Dextran ◽

Extracellular Materials ◽

Foreign Materials ◽

Cell Medium ◽

Delivery Efficiency

Delivering extracellular materials into adherent cells presents several challenges. A homemade photoporation platform, mediated by gold nanoparticles (AuNPs), was constructed to find a suitable method for finding all adherent cells in this process with high delivery efficiency. The thermal dynamics of AuNPs could be monitored. Based on this system, 60 nm AuNPs were selected to be attached to cells for optimal photoporation. After irradiating the cells covered with AuNPs using a nanosecond pulse laser, fluorescein isothiocyanate-dextran in the medium were delivered into optoporated adherent HeLa (human cervical cell lines) cells. The delivery efficiency and cell viability of this process were evaluated using a fluorescence microscope and flow cytometry. The experimental results showed that targeting cells using antibodies, laser irradiation from the top of the cell culture well, and reducing the cell medium are important for improving the delivery efficiency. The optimal loading efficiency for adherent HeLa cells was 53.4%.

Download Full-text