Two distinct D-amino acid dehydrogenases, each showing absolute speci&ity for methylene blue or 2,6-dichloroindophenol, respectively, were isolated from Pseudomonas @orescens (ATCC 11299B). The methylene blue-specific ~-amino acid dehydrogenase was detectable only in extracts from D-tryptophan-grown cells and was purified about 40-fold. The 2,6-dichloroindophenol-specif?c ~-amino acid dehydroge...

The optical sensor for "tea catechins" was built by immobilizing 2,2'-(1,4-phenylenedivinylene)bis-8-hydroxyquinoline (PBHQ) on TiO₂ nanoparticles (NPs). The sensor worked by "indophenol blue" dye formation on PBHQ-immobilized TiO₂ NPs as a result of p-aminophenol (PAP) autoxidation with dissolved O₂ at pH 10. Among quercetin, rutin, naringenin, naringin, gallic acid, caffeic acid, ferulic acid...

Perovskite quantum dots (PQDs) have fascinating optoelectronic properties, such as high photoluminescence yield (PLQY) for a broad range of materials, and the possibility to obtain different bandgaps with same material or halide combinations. Nevertheless, blue-emissive materials generally present limited PLQY color instability. Here, two molecular organogels, based on derivative an amino acid ...

Indole-3-acetic acid (plant auxin) has low toxicity but dramatically enhances the killing of mammalian cells on illuminating phenothiazinium dyes with red light. Suitable dyes include toluidine blue, used in cancer diagnosis because of localization in tumors, and methylene blue, used in experimental photodynamic therapy of cancer. The photosensitized oxidation of indole acetic acid forms a free...

Spectral tuning by visual pigments involves the modulation of the physical properties of the chromophore (11-cis-retinal) by amino acid side chains that compose the chromophore-binding pocket. We identified 12 amino acid residues in the human blue cone pigment that might induce the required green-to-blue opsin shift. The simultaneous substitution of nine of these sites in rhodopsin (M86L, G90S,...

The phosphomolybdic acid (PMA) has been used as an adsorbent for the removal of dyes (Methylene blue and Congo red dye) from synthetic aqueous solution. Different factors of the adsorbent, like, contact time, pH of the sorption medium, concentration of the dye solution, were investigated by the batch sorption experiment. The adsorption equilibrium data was best fitted by the Langmuir isotherm m...

We have investigated the photoluminescence ~PL! from anodic alumina membranes with an ordered nanopore array formed on bulk Al foils. Most of the membranes fabricated by anodization in oxalic acid showed a strong PL peak in the blue. Due to an obvious asymmetry, the PL peak can be Gaussian divided into two bands around 405 and 455 nm, having a slight shift with the sample formed in different ac...

Ammonium molybdate, in acid solution, is reduced to an oxide stage, with the production of a blue color, by many substances of biological importance. Our attention was first attracted to this subject through an accidental observation. We were engaged in the attempt to work out a technique for the nephelometric estimation of phosphoric acid, using a heavy solution of cane sugar for the medium of...

Fleming’s (1) observation that cystine in the presence of ferric ions forms a blue color when heated with p-aminodimethylanilinc suggested the application of this reaction to a quantitative estimation of cystine in ,biological materials. The formation of the blue color occurs in strongly acid solution, which enhances the value of the reaction as a means of estimating cystine in the acid hydroly...

Indole-3-acetic acid (plant auxin) has low toxicity but dramatically enhances the killing of mammalian cells on illuminating phenothiazinium dyes with red light. Suitable dyes include toluidine blue, used in cancer diagnosis because of localization in tumors, and methylene blue, used in experimental photodynamic therapy of cancer. The photosensitized oxidation of indole acetic acid forms a free...