A new highly selective and sensitive colorimetric chemosensor 1 for Co(2+) was developed. The receptor 1 sensed Co(2+) by changing its color from yellow to orange in aqueous solution. Moreover, 1 could be used as a practical, visible colorimetric test kit for Co(2+).

The synthesis of a novel aza-BODIPY dye functionalized with fused pyrazine rings, suitable for use as a selective colorimetric and fluorometric sensor for NH(4)(+), is outlined. In addition to significant fluorescence quenching, an obvious colorimetric change from green to red-pink is observed enabling facile "naked-eye" detection of NH(4)(+).

The objective of the present work was to compare colorimetric and distillationÈtitration methods to determine the ammonia-nitrogen con3 centration in sheep and goat urine samples. Colorimetric methods used were based on the indophenol reaction, whereas titrimetric methods were based on the alkali distillation of ammonia from the urine and its titrimetric determination with a standard acid. Colo...

In a recent study (1 ) of diabetic patients with hemoglobins S and C (Hb S and Hb C), we showed a significant decrease in the proportion of glycosylated Hb, as measured by cation-exchange chromatography. We suggested ( I ) that these low values for glycosylated Hb might be caused by the inability of either Hb S or Hb C to undergo glycosylation or by their failure to be eluted from the column wi...

Gold and Silver nanoparticles (AuNPs AgNPs) are perfect platforms for developing sensing colorimetric devices thanks to their high surface volume ratio distinctive optical properties, particularly sensitive changes in the surrounding environment. These characteristics ensure sensitivity devices. Au Ag can be capped with suitable molecules that act as specific analyte receptors, so highly select...

As part of our ongoing research into the clear daytime sky's visible structure, we analyze over 1,500 skylight spectra measured during a seven-month period in Granada, Spain. We use spectral radiances measured within 3 degrees fields of view (FOV's) to define colorimetric characteristics along four sky meridians: the solar meridian and three meridians at azimuths of 45 degrees, 90 degrees, and ...

Colorimetric recognition and sensing of sulfide with high selectivity by virtue of glutathione-modified gold nanoparticle (GSH-AuNP) is presented. The assay is developed based on a specific anion-for-molecule ligand exchange reaction, through which sulfide replaces glutathione self-assembled on the AuNP. The unique feature of the GSH-AuNP probe makes it a novel colorimetric sensor for sulfide.

Pyrophosphate anions play key roles in various biological and chemical processes. During the last few years, many exciting results have emerged regarding the development of fluorescent and colorimetric sensors for this biologically important species. In this review, we will cover the fluorescent and colorimetric chemosensors developed for the detection of pyrophosphate (PPi) since 2010.

We describe a modified colorimetric method for determining procainamide in plasma by use of a diazotization and coupling reaction with N-(1-naphthyl)-ethylenediamine dihydrochloride (Marshall's reagent). The sensitivity of the assay is increased twofold over the originally reported colorimetric method, and the lower limit of detection for the assay of a 1.0-ml plasma sample has been decreased t...

A novel colorimetric method to quantify tannase activity of viable tannase-producing bacterial strains was developed through application of a visual reading method that was to detect the activity qualitatively. The novel method was sensitive enough to quantify the marginal tannase activity of strains that could not be otherwise measured by conventional spectrophotometric or colorimetric methods.