Effect of β-cyclodextrin on intra and intermolecular Michael addition of some catechol derivatives
作者:Lida Khalafi、Mohammad Rafiee、Sahar Fathi
DOI:10.1016/j.saa.2013.09.029
日期:2014.1
nature of catechol derivatives. The observed homogeneous rate constants of the reactions were estimated by fitting the absorption time profiles for each reaction. The effect of β-cyclodextrin and its inclusion complex has also been studied on the chosen reactions. The formation constants of the complexes of catechol, dopamine and epinephrine with β-cyclodextrin as well as the rate constants of the reactions
Immobilization of tyrosinase on Fe3o4@Au core–shell nanoparticles as bio-probe for detection of dopamine, phenol and catechol
作者:Elham Arkan、Changiz Karami、Ronak Rafipur
DOI:10.1007/s00775-019-01691-0
日期:2019.10
AbstractAn optical bio-probe based on the immobilizedtyrosinase on the surface of Fe3O4@Au was described for the detection of dopamine, phenol and catechol. The prepared bio-probe (Fe3O4@Au@tyrosinase) was characterized by means such as TEM, SEM, VSM, DLS and TGA. In the presence of the bio-probe, the phenol, catechol and dopamine were converted to benzoquinone, o-quinone and dopaquinone, and the
摘要描述了一种基于Fe 3 O 4 @Au表面固定化酪氨酸酶的光学生物探针,用于检测多巴胺,苯酚和儿茶酚。制备的生物探针(Fe 3 O 4(Au @酪氨酸酶)通过诸如TEM,SEM,VSM,DLS和TGA的方法表征。在存在生物探针的情况下,苯酚,儿茶酚和多巴胺被转化为苯醌,邻苯二酚和多巴醌,荧光光谱分别出现在308 nm,329 nm和336 nm处,ex = 270 nm。然而,通过增加生物探针中酚类化合物的浓度,产物(苯醌,邻苯二酚和多巴醌)的量增加,这是荧光强度增加的原因。使用这种机制,设计了一种生物探针,使得荧光光谱的强度在不同时间段后随底物浓度的增加而成比例地增加。将0.003 mg / mL的酪氨酸酶加载到1.65 mg / mL的Fe 3 O 4上@Au。在室温和pH 6.8下证明了生物探针的最高性能。通过研究生物探针对不同酚类化合物的响应特性,发现该生物探针在5.0–75.0
A non-covalent functionalization of copper tetraphenylporphyrin/chemically reduced graphene oxide nanocomposite for the selective determination of dopamine
A non‐covalent functionalization based on a coppertetraphenylporphyrin/chemically reduced graphene oxide (Cu‐TPP/CRGO) nanocomposite is demonstrated for selective determination of dopamine (DA) in pharmaceutical and biological samples. A homogeneous electron‐rich environment can be created on the graphene surface by Cu‐TPP due to the π–π non‐covalent stacking interaction. The synthesized Cu‐TPP/CRGO
Studies of the competing rates of catechol oxidation and suicide inactivation of tyrosinase
作者:Christopher A. Ramsden、Patrick A. Riley
DOI:10.3998/ark.5550190.0011.a20
日期:——
Tyrosinaseoxidation of catechols to ortho-quinones is accompanied by suicide inactivation of the enzyme. The rates of these competing processes vary and depend on the nature of ring substituents. For a series of 4-substituted catechols the relationships between structure and reaction rates have been examined using multiple regression. Significant but different structurerate relationships were found
A new electrochemical sensor based on a nitrogen-doped graphene/CuCo<sub>2</sub>O<sub>4</sub> nanocomposite for simultaneous determination of dopamine, melatonin and tryptophan
作者:F. Tadayon、Z. Sepehri
DOI:10.1039/c5ra12020a
日期:——
An electrochemical sensor was fabricated for the simultaneous determination of dopamine, melatonin and tryptophan in biological and pharmaceutical samples.