scholarly journals A biomimetic cerium-based biosensor for the direct visual detection of phosphate under physiological conditions

2019 ◽  
Vol 55 (99) ◽  
pp. 14894-14897
Author(s):  
Thibaud Rossel ◽  
Marc Creus
Keyword(s):  
Aqueous Medium ◽  
Visual Detection ◽  
Physiological Conditions ◽  
Neutral Ph ◽  
Phosphate Ions ◽  
Displacement Assay

An indicator displacement assay (IDA) was used to probe phosphate ions in an aqueous medium at neutral pH using a dinuclear cerium based complex [Ce2(HXTA)]3+.

A biomimetic cerium-based biosensor for the direct visual detection of phosphate under physiological conditions

2019 ◽  
Author(s):  
Thibaud Rossel ◽  
Marc Creus
Keyword(s):  
Visual Detection ◽  
Detection System ◽  
Physiological Conditions ◽  
Naked Eye ◽  
Neutral Ph ◽  
Phosphate Ions ◽  
Homoleptic Complex ◽  
Displacement Assay

<div><div><div><p> </p><p>An indicator displacement assay (IDA) was used to probe phosphate ions in acqueous medium at neutral pH using a dinuclear cerium based complex [Ce<sub>2</sub>(HXTA)]3+. The homoleptic complex can be used to detect phosphate ions in micromolar concentrations either spectrophotometrically or with the naked-eye. To our knowledge, this is the biomimetic detection system with the highest affinity known to date for selective, naked-eye based phosphate recognition under physiological conditions.</p> </div></div></div>

scholarly journals A biomimetic cerium-based biosensor for the direct visual detection of phosphate under physiological conditions

2019 ◽  
Author(s):  
Thibaud Rossel ◽  
Marc Creus
Keyword(s):  
Visual Detection ◽  
Detection System ◽  
Physiological Conditions ◽  
Naked Eye ◽  
Neutral Ph ◽  
Phosphate Ions ◽  
Homoleptic Complex ◽  
Displacement Assay

<div><div><div><p> </p><p>An indicator displacement assay (IDA) was used to probe phosphate ions in acqueous medium at neutral pH using a dinuclear cerium based complex [Ce<sub>2</sub>(HXTA)]3+. The homoleptic complex can be used to detect phosphate ions in micromolar concentrations either spectrophotometrically or with the naked-eye. To our knowledge, this is the biomimetic detection system with the highest affinity known to date for selective, naked-eye based phosphate recognition under physiological conditions.</p> </div></div></div>

scholarly journals A remarkable fluorescent cerium-based chemosensor for selective phosphate detection in aquaeous medium

2020 ◽  
Author(s):  
Thibaud Rossel
Keyword(s):  
Aqueous Medium ◽  
Chemical Properties ◽  
Cerium Ammonium Nitrate ◽  
Naked Eye ◽  
High Affinity ◽  
Phosphate Ions ◽  
Homoleptic Complex ◽  
Displacement Assay ◽  
Phosphate Detection ◽  
Naked Eye Detection

<p>Phosphates anions are important molecules for the society in general and involved for example in medicine or agriculture. Detection of them with chemosensor is a challenge due to the chemical properties of the anions. In this context, an exquisite chemosensor would have exquisite affinity, selectivity and low detection limit. Here we address this problem using a simple fluorescent indicator displacement assay (FID) with only commercially available chemicals used to probe phosphate ions in aqueous medium using cerium ammonium nitrate (CAN). The monomeric homoleptic complex detects phosphate ions in low millimolar concentrations either spectrophotometrically or with the naked-eye with high selectivity over other anions and high affinity. To our knowledge, this is the first description of a simple sensitive, selective and high affinity cerium-based chemosensor for the fluorescent selective naked-eye detection of phosphate in aqueous medium. It proved useful for the detection of phosphate in Coca Cola. </p>

scholarly journals Biocomposite application for the phosphate ions removal in aqueous medium

2018 ◽  
Vol 7 (3) ◽  
pp. 300-307 ◽  
Author(s):  
Haq Nawaz Bhatti ◽  
Javeria Hayat ◽  
Munawar Iqbal ◽  
Saima Noreen ◽  
Sadia Nawaz
Keyword(s):  
Aqueous Medium ◽  
Phosphate Ions

scholarly journals An Acid-activated Nucleobase Transporter from Leishmania major

2009 ◽  
Vol 284 (24) ◽  
pp. 16164-16169 ◽  
Author(s):  
Diana Ortiz ◽  
Marco A. Sanchez ◽  
Hans P. Koch ◽  
H. Peter Larsson ◽  
Scott M. Landfear
Keyword(s):  
Leishmania Major ◽  
De Novo ◽  
Low Ph ◽  
Acidic Ph ◽  
Physiological Conditions ◽  
Neutral Ph ◽  
Amastigote Stage ◽  
Electrode Voltage ◽  
Ph Conditions ◽  
Micromolar Range

Parasitic protozoa are unable to synthesize purines de novo and must import preformed purine nucleobases or nucleosides from their hosts. Leishmania major expresses two purine nucleobase transporters, LmaNT3 and LmaNT4. Previous studies revealed that at neutral pH, LmaNT3 is a broad specificity, high affinity nucleobase transporter, whereas LmaNT4 mediates the uptake of only adenine. Because LmaNT4 is required for optimal viability of the amastigote stage of the parasite that lives within acidified phagolysomal vesicles of mammalian macrophages, the function of this permease was examined under acidic pH conditions. At acidic pH, LmaNT4 acquires the ability to transport adenine, hypoxanthine, guanine, and xanthine with Km values in the micromolar range, indicating that this transporter is activated at low pH. Thus, LmaNT4 is an acid-activated purine nucleobase transporter that functions optimally under the physiological conditions the parasite is exposed to in the macrophage phagolysosome. In contrast, LmaNT3 functions optimally at neutral pH. Two-electrode voltage clamp experiments performed on LmaNT3 and LmaNT4 expressed in Xenopus oocytes revealed substrate-induced inward directed currents at acidic pH, and application of substrates induced acidification of the oocyte cytosol. These observations imply that LmaNT3 and LmaNT4 are nucleobase/proton symporters.

Gastroduodenal mucus bicarbonate barrier: protection against acid and pepsin

2005 ◽  
Vol 288 (1) ◽  
pp. C1-C19 ◽  
Author(s):  
Adrian Allen ◽  
Gunnar Flemström
Keyword(s):  
Ph Gradient ◽  
Support Surface ◽  
First Line ◽  
Physiological Conditions ◽  
Neutral Ph ◽  
Primary Function ◽  
Gel Layer ◽  
Mucus Gel ◽  
And Control

Secretion of bicarbonate into the adherent layer of mucus gel creates a pH gradient with a near-neutral pH at the epithelial surfaces in stomach and duodenum, providing the first line of mucosal protection against luminal acid. The continuous adherent mucus layer is also a barrier to luminal pepsin, thereby protecting the underlying mucosa from proteolytic digestion. In this article we review the present state of the gastroduodenal mucus bicarbonate barrier two decades after the first supporting experimental evidence appeared. The primary function of the adherent mucus gel layer is a structural one to create a stable, unstirred layer to support surface neutralization of acid and act as a protective physical barrier against luminal pepsin. Therefore, the emphasis on mucus in this review is on the form and role of the adherent mucus gel layer. The primary function of the mucosal bicarbonate secretion is to neutralize acid diffusing into the mucus gel layer and to be quantitatively sufficient to maintain a near-neutral pH at the mucus-mucosal surface interface. The emphasis on mucosal bicarbonate in this review is on the mechanisms and control of its secretion and the establishment of a surface pH gradient. Evidence suggests that under normal physiological conditions, the mucus bicarbonate barrier is sufficient for protection of the gastric mucosa against acid and pepsin and is even more so for the duodenum.

scholarly journals The role of link-protein in the structure of cartilage proteoglycan aggregates

1979 ◽  
Vol 177 (1) ◽  
pp. 237-247 ◽  
Author(s):  
T E Hardingham
Keyword(s):  
Analytical Ultracentrifugation ◽  
Free Form ◽  
Link Protein ◽  
Physiological Conditions ◽  
Neutral Ph ◽  
Laryngeal Cartilage ◽  
Cartilage Proteoglycan ◽  
Proteoglycan Aggregates

Proteoglycan fractions were prepared from pig laryngeal cartilage. The effect of link-protein on the properties of proteoglycan-hyaluronate aggregates was examined by viscometry and analytical ultracentrifugation. Aggregates containing link-protein were more stable than link-free aggregates at neutral pH, at temperatures up to 50 degrees C and in urea (up to 4.0M). Oligosaccharides of hyaluronate were able to displace proteoglycans from link-free aggregates, but not from the link-stabilized aggregates. Both types of aggregate were observed in the ultracentrifuge, but at the concentration investigated (less than 2 mg/ml) the link-free form was partially dissociated and the proportion aggregated varied with the pH and temperature and required more hyaluronate for saturation than did link-stabilized aggregate. The results showed that link-protein greatly strengthened the binding of proteoglycans to hyaluronate and suggest that under physiological conditions it ‘locks’ proteoglycans on to the hyaluronate chain.

scholarly journals An astonishing simple cerium-based chemosensor for fluorescent selective phosphate detection in aquaeous medium

2020 ◽  
Author(s):  
Thibaud Rossel
Keyword(s):  
High Selectivity ◽  
Chemical Properties ◽  
Cerium Ammonium Nitrate ◽  
Naked Eye ◽  
The Past ◽  
Phosphate Ions ◽  
Cerium Ammonium ◽  
Displacement Assay ◽  
Phosphate Detection ◽  
Naked Eye Detection

<div><div><div><p>Phosphate ions are socially important chemicals. They are involved in crucial processes such as for example in medicine or agriculture. However, their sensing with a chemosensor is ardous due to their chemical properties. In this context, a remarkable chemosensor would reveal an outstanding affinity, a high selectivity and a low detection limit in favor of an analyte. This has long been addressed in the past by chemists in synthesizing com- plex chemical architectures as receptors but with questionable successes. Astonishingly, here, for phosphate detection, we address this problem profiting by a simple fluorescent indicator displacement assay (FID) with only commercially available chemicals. We used cerium ammonium nitrate (CAN) combined with a fluorophore to probe phosphate ions in aqueous mediums. The inorganic complex detects phosphate ions in low millimolar concentrations either spectrophotometrically or with the naked-eye with high selectivity and affinity over other anions. To our knowledge, this is the first description of a simple sensitive, selective and high affinity cerium-based chemosensor for the fluorescent selective naked-eye detection of phosphate in aqueous medium. It proved useful for the detection of phosphate in Coca-Cola©.</p></div></div></div>

scholarly journals An astonishing simple cerium-based chemosensor for fluorescent selective phosphate detection in aquaeous medium

2021 ◽  
Author(s):  
Thibaud Rossel
Keyword(s):  
High Selectivity ◽  
Chemical Properties ◽  
Cerium Ammonium Nitrate ◽  
Naked Eye ◽  
The Past ◽  
Phosphate Ions ◽  
Cerium Ammonium ◽  
Displacement Assay ◽  
Phosphate Detection ◽  
Naked Eye Detection

<div><div><div><p>Phosphate ions are socially important chemicals. They are involved in crucial processes such as for example in medicine or agriculture. However, their sensing with a chemosensor is ardous due to their chemical properties. In this context, a remarkable chemosensor would reveal an outstanding affinity, a high selectivity and a low detection limit in favor of an analyte. This has long been addressed in the past by chemists in synthesizing com- plex chemical architectures as receptors but with questionable successes. Astonishingly, here, for phosphate detection, we address this problem profiting by a simple fluorescent indicator displacement assay (FID) with only commercially available chemicals. We used cerium ammonium nitrate (CAN) combined with a fluorophore to probe phosphate ions in aqueous mediums. The inorganic complex detects phosphate ions in low millimolar concentrations either spectrophotometrically or with the naked-eye with high selectivity and affinity over other anions. To our knowledge, this is the first description of a simple sensitive, selective and high affinity cerium-based chemosensor for the fluorescent selective naked-eye detection of phosphate in aqueous medium. It proved useful for the detection of phosphate in Coca-Cola©.</p></div></div></div>

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