Urea-containing oligomers/polymers as chemosensors for visual detection of phosphate anions

The article discusses the role of conjugated lactic acid/ lactate anion (LacH/Lac-) and dihydrogenphosphate anion/ hydrogenphosphate anion (H2PO4-/HPO42-) pairs in the formation of the buffer properties of tissue as a factor determining pH. The buffer properties of homogenates of the tissue of adenocarcinoma of the mammary gland and the adjacent tissue were quantitatively characterized by the buffer capacity which was determined by potentiometric titration. The concentrations of acid anions were determined spectrophotometrically. The material was biopsy specimens of mammary gland adenocarcinoma (T1-4, N0-1, M0) and adjacent tissue of 22 patients aged from 33 to 75 years. It was found that the buffer capacity of tumors is in 2.5 times higher than in normal tissue. It was established that for the tumor tissue, the buffer capacity of the LacH/Lac- system is in 3 times higher, and the buffer capacity of the H2PO4-/HPO42-system is in 2.5 times greater than for normal untransformed tissue. Concentrations of lactate anions (1,93 ± 0,50 vs 0,57 ± 0,22; p <0.001) and phosphate anions (2,54 ± 0,39 vs 0,70 ± 0,19; p <0,001) in homogenates of the tumor tissue were significantly higher in tumor tissue in comparison with the adjacent tissue. A strong correlation was found between the concentration of phosphate anions and the buffer capacity for tumor tissue (r = 0,857; p = 0,002) and for adjacent tissue (r = 0,917; p <0,001). The correlation between the concentration of lactate anions and the buffer capacity for tumor tissues can be estimated as average (r = 0,626; p = 0,053), while it is absent for the adjacent tissue (r = 0,494; p = 0,147). The results suggest that the acid-base properties of homogenates of mammary adenocarcinoma tissues are determined by two buffer systems: LacH/Lac- and H2PO4-/HPO42-, while the intracellular acid-base homeostasis of non-transformed tissues is mainly determined by the H2PO4-/HPO42- system.

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Mechanism for Visual Detection of Small Targets in Insects

10.21236/ada595006 ◽

2013 ◽

Author(s):

David C. O'Carroll ◽

Steven D. Wiederman ◽

Patrick A. Shoemaker

Keyword(s):

Visual Detection ◽

Small Targets

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Dual-emission color-controllable nanoparticle based molecular imprinting ratiometric fluorescence sensor for the visual detection of Brilliant Blue

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2018.12.134 ◽

2019 ◽

Vol 284 ◽

pp. 428-436 ◽

Cited By ~ 15

Author(s):

Qian Yang ◽

Jinhua Li ◽

Xiaoyan Wang ◽

Hailong Peng ◽

Hua Xiong ◽

...

Keyword(s):

Molecular Imprinting ◽

Visual Detection ◽

Fluorescence Sensor ◽

Brilliant Blue ◽

Ratiometric Fluorescence ◽

Dual Emission ◽

Emission Color

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Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials

Sustainability ◽

10.3390/su13031502 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1502

Author(s):

Maria Xanthopoulou ◽

Dimitrios Giliopoulos ◽

Nikolaos Tzollas ◽

Konstantinos S. Triantafyllidis ◽

Margaritis Kostoglou ◽

...

Keyword(s):

Sorption Capacity ◽

Removal Rate ◽

Phosphate Concentration ◽

Phosphate Removal ◽

Equilibrium Studies ◽

Maximum Sorption Capacity ◽

Algae Blooms ◽

Maximum Sorption ◽

Phosphate Anions ◽

Adsorbent Dose

In water and wastewater, phosphate anions are considered critical contaminants because they cause algae blooms and eutrophication. The present work aims at studying the removal of phosphate anions from aqueous solutions using silica particles functionalized with polyethylenimine. The parameters affecting the adsorption process such as pH, initial concentration, adsorbent dose, and the presence of competitive anions, such as carbonate, nitrate, sulfate and chromate ions, were studied. Equilibrium studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. The adsorption isotherm data fitted well with the Langmuir and Sips model. The maximum sorption capacity was 41.1 mg/g at pH 5, which decreased slightly at pH 7. The efficiency of phosphate removal adsorption increased at lower pH values and by increasing the adsorbent dose. The maximum phosphate removal was 80% for pH 5 and decreased to 75% for pH 6, to 73% for pH 7 and to 70% for pH 8, for initial phosphate concentration at about 1 mg/L and for a dose of adsorbent 100 mg/L. The removal rate was increased with the increase of the adsorbent dose. For example, for initial phosphate concentration of 4 mg/L the removal rate increased from 40% to 80% by increasing the dose from 0.1 to 2.0 g/L at pH 7. The competitive anions adversely affected phosphate removal. Though they were also found to be removed to a certain extent. Their co-removal provided an adsorbent which might be very useful for treating waters with low-level multiple contaminant occurrence in natural or engineered aquatic systems.

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