Search results for "Benzidine"
showing 8 items of 8 documents
Colorimetic biosensing dispositive based on reagentless hybrid biocomposite: Application to hydrogen peroxide determination
2016
Abstract An efficient approach to enhance the performance of colorimetric biosensors has been developed. The biosensor is based on the co-immobilization of the reagent 3,3′,5,5′-teramethylbencidine (TMB) and the enzyme horseradish peroxidase (HRP) in a PDMS-TEOS-SiO2NPs support. The HRP, in presence of H2O2, catalyzes the oxidation of TMB, producing a blue color. The generated biosensor, doped with the substrate (TMB) and the enzyme (HRP) (entrapped or adsorbed), has been used to determine H2O2 in real samples. Firstly, the immobilization of TMB and HRP in the composite has been studied in order to find the best suitable configuration. The kinetic parameters Vmax (maximum reaction rate) and…
Cannabinoid control of brain bioenergetics: Exploring the subcellular localization of the CB1 receptor
2014
Brain mitochondrial activity is centrally involved in the central control of energy balance. When studying mitochondrial functions in the brain, however, discrepant results might be obtained, depending on the experimental approaches. For instance, immunostaining experiments and biochemical isolation of organelles expose investigators to risks of false positive and/or false negative results. As an example, the functional presence of cannabinoid type 1 (CB1) receptors on brain mitochondrial membranes (mtCB1) was recently reported and rapidly challenged, claiming that the original observation was likely due to artifact results. Here, we addressed this issue by directly comparing the procedures…
Electrolyte-driven electrochemical amplification by poly(thienylacetylene) encapsulated within Zeolite Y
2006
Electrochemical oxidation and reduction of poly(thienylacetylene) encapsulated inside zeolite Y (PTA@Y) exhibit with large anodic and cathodic doping currents with a significant reversibility. Thienyl groups lower the redox potential of polyacetylene chain whereas encapsulation stabilizes the resulting charged radical species blocking undesired post electron-transfer cross-link reactions. Size-exclusion effects associated produces an electrolyte-dependent amplification of currents recorded at PTA@Y-modified electrodes for electrochemical processes involving selected substrates in solution, namely, dinitrobiphenyl and benzidine. Keywords: Poly(thienylacetylene), Zeolite Y, Electrochemistry, …
Investigation of bloodstains: false negative results of the benzidine test
1995
Since the discovery of the Benzidine Test, this method has been considered absolutely reliable for the generic diagnosis of bloodstains. The authors reviewed support the existence of false positive results, as the subtract in the coloration reaction the peroxidases may be found in numerous natural products [ 11. There is also general agreement with the false negative results: a negative result provided by the Benzidine Test indicates that the stain is not blood [2]. Given the strong certainty offered by most works of forensic medicine and criminology, most countries Spain included use this technique as a screening method in the investigation of bloodstains: when the result is negative the i…
Screening of some banned aromatic amines in textile products from Indian bandhani and gamthi fabric and in human sweat using micellar liquid chromato…
2021
Certain dyes in textile products, which are capable of reductively splitting into carcinogenic aromatic amines, are strictly controlled in many countries. A simple, rapid, sensitive and green chromatographic method has been developed and validated for the simultaneous determination of 4-aminophenol (4-AMP), p-phenylenediamine (p-PPD) and benzidine (BNZ), banned aromatic amines in dyeing clothes and human sweat. The separation was achieved using a micellar mobile phase of 0.1 M SDS, 4% 1- butanol (v/v) buffered to pH 7 with sodium dihydrogen phosphate, flowing under isocratic mode at 1 mL/min through a C18 column. Photodiode array detector was set at 210 nm. Using the above chromatographic c…
Outstandingly robust anodic dehydrogenative aniline coupling reaction
2020
Abstract Oxidative treatment of anilines usually leads to the formation of black polymers, often referred to as “aniline black”. This over-oxidation is hardly controllable and also a challenging task in the anodic conversion of anilines. Here, a quick and efficient access to valuable building blocks by anodic cross- and homo-coupling of aniline and benzidine derivatives is reported. This electrosynthesis is easily performed in a simple undivided cell using constant current conditions. The key to the observed outstanding performance and robustness of this system is attributed to the used solvent 1,1,1,3,3,3-hexafluoroisopropanol. The extraordinary performance over a broad range of current de…
Über die reduktion von polyacrylsäurederivaten
1960
Bei der Reduktion von Polyacrylsaurechlorid und von Polyacrylsaure-N-methylanilid mit Lithiumaluminium-tri-tert.-butoxyhydrid bzw. Lithiumaluminiumhydrid entstehen Polymere mit 30–50 Mol-% Aldehydgruppen. Aus Polyacrylsaurechloriden, Polyacrylsauremethylestern und Polyacroleinen wurden bei der Reduktion mit Lithiumaluminiumhydrid bzw. Kaliumborhydrid identische polymere Allylalkohole erhalten. Diese lassen sich acylieren, tritylieren und tosylieren. Die Polyallyl- und Polyvinyl-dinitrobenzoate bilden mit α-Naphthylamin und Benzidin gefaurbte Molekulverbindungen. The reduction of polyacrylyl chloride and polyacryl-N-methylanilide with lithium aluminum tri-tert-butoxyhydride and lithium alumi…
Ultrasensitive and highly specific detection of iodine ions using zirconium (IV)-enhanced oxidation
2022
Nuclear energy has significantly promoted the development of human society. However, nuclear pollution caused by nuclear accidents can lead to significant hazards to the environment and human health. As a major radioactive product, radioactive iodine (mainly existing as I−) detection has attracted significant attentions. In this study, zirconium(IV) is used to enhance the oxidation of environmental I− to form I2. Subsequently, the generated I2 oxidizes the chemical chromogenic substrate 3,3′,5,5′-tetramethylbenzidine, which is used for I− detection and realizes an ultralow limit of detection (LoD) of 0.176 nM. The LoD of our method, to the best of our knowledge, is the lowest among those of…