Synthesis of ZnO nanorods-Au nanoparticles hybrids via in-situ plasma sputtering-assisted method for simultaneous electrochemical sensing of ascorbic acid and uric acid

2016 ◽  
Vol 666 ◽  
pp. 178-184 ◽  
Author(s):  
Chao Hou ◽  
Hongying Liu ◽  
Dan Zhang ◽  
Chi Yang ◽  
Mingzhen Zhang
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Au Nanoparticles ◽  
Zno Nanorods ◽  
Electrochemical Sensing ◽  
Plasma Sputtering

Is idiopathic recurrent calcium urolithiasis in males a cellular disease? Laboratory findings in plasma, urine and erythrocytes, emphasizing the absence and presence of stones, oxidative and mineral metabolism: an observational study

2005 ◽  
Vol 43 (6) ◽  
Author(s):  
Paul Otto Schwille ◽  
Mahimaidos Manoharan ◽  
Angelika Schmiedl
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Plasma Levels ◽  
Mineral Metabolism ◽  
Stone Formation ◽  
Healthy Controls ◽  
Laboratory Findings ◽  
Cross Sectional ◽  
Calcium Urolithiasis

AbstractBackground: The site of origin of idiopathic recurrent calcium urolithiasis (IRCU) – a disorder characterized by stones composed of calcium oxalate (CaOx) and/or calcium phosphate (CaPi) – is uncertain, because in urine such risk factors for stones as disturbed Ox, Ca and Pi are not regularly observed. Aims: To evaluate whether imbalance of antioxidants and oxidants might be present in IRCU patients that is then followed by abnormal urine, plasma and intracellular mineral homeostasis, and stones. Methods: Males were investigated in the laboratory under standardized conditions, and three trials were organized. Trial 1 was cross-sectional, comparing IRCU patients with (n=111) and without stones in situ (n=126), focussing on abnormalities of oxypurines and minerals in urine and plasma, and metabolic activity (MA) of the disease. Trial 2 was partly controlled (n=14 healthy subjects; n=53 IRCU patients), comparing the plasma levels of total antioxidant status (TAS) and uric acid, the major antioxidant in humans, using the subsets Low (n=26) and High (n=27) TAS among IRCU patients in terms of plasma levels of uric acid, ascorbic acid, albumin, α-tocopherol and minerals, urinary minerals, CaOx and CaPi (hydroxyapatite) supersaturation. Trial 3, comprising stone-free IRCU patients (n=8) and healthy controls (n=8), compared minerals and mineral ratios in plasma and red blood cells (RBCs). Established analytical methodologies were used throughout. Results: In trial 1, uricemia, hypoxanthinuria and proteinuria were elevated, fractional urinary clearance (FE) of uric acid was decreased in stone-bearing patients, and MA correlated positively with uricemia and urinary total protein excretion. In trial 2, TAS was significantly decreased in IRCU patients vs. healthy controls; low TAS coincided with low plasma uric acid and albumin, unchanged ascorbic acid, α-tocopherol and parathyroid hormone, but increased FE-uric acid and Pi excretion; the latter correlated negatively with TAS. In trial 3, plasma minerals were significantly decreased in IRCU patients vs. controls, and Ca/Pi, (Ca/Pi)/Mg and (Ca/Pi)/Na molar ratios increased; the latter ratio was also increased in RBCs, and correlated highly positively with the same ratio in plasma. Conclusions: In IRCU 1) renal stones in situ in combination with high fasting uricemia, high hypoxanthinuria and protein-uria, and high MA suggest that a systemic metabolic anomaly underlies stone formation; 2) antioxidant deficit is frequent, unrelated to the presence or absence of stones but apparently related to poor renal uric acid recycling, low uricemia and albuminemia, exaggerated urinary Pi excretion, and low MA; 3) the combination of low plasma TAS, disordered Ca/Pi and other mineral ratios in urine, plasma and RBCs, but unchanged urinary Ca salt supersaturation is compatible with the view that CaPi solid and Ca microlith formation start inside oxidatively damaged cells.

Simultaneous determination of dopamine, ascorbic acid and uric acid using a multi-walled carbon nanotube and reduced graphene oxide hybrid functionalized by PAMAM and Au nanoparticles

2015 ◽  
Vol 7 (4) ◽  
pp. 1471-1477 ◽  
Author(s):  
Siyuan Wang ◽  
Wen Zhang ◽  
Xia Zhong ◽  
Yaqin Chai ◽  
Ruo Yuan
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Simultaneous Determination ◽  
Au Nanoparticles ◽  
Electrochemical Determination ◽  
Multi Walled Carbon Nanotube ◽  
Reduced Graphene

A nanohybrid (RGO–PAMAM–MWCNT–AuNPs) for simultaneous electrochemical determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) was reported in this paper.

Two-Photon Sensing of Dopamine by Using Au Nanoparticles

2015 ◽  
Vol 738-739 ◽  
pp. 31-37
Author(s):  
Cui Feng Jiang ◽  
Neng Yue Gao ◽  
Qi Sheng Wu ◽  
Yu Sun ◽  
Qing Hua Xu
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Detection Limit ◽  
Metal Ions ◽  
Gold Nanoparticle ◽  
Au Nanoparticles ◽  
Cross Linking ◽  
Au Nps ◽  
Two Photon ◽  
Catechol Group

In this paper, we demonstrated a gold nanoparticle based two-photon photoluminescence (TPPL) assay for the detection of dopamine with the detection limit of 0.3 μM. Protonated dopamine molecules can bind bidentately to surface of gold atoms through the catechol group. The adsorption of dopamine displaces the stabilizing agent of citrate groups, and neutralizes the charge of solution, resulting in non-cross linking aggregation of Au NPs. Aggregation of Au NPs could induce significantly enhanced TPPL. Thus, a simple TPPL assay was designed. We have shown that when Au NPs solution was mixed with dopamine, TPPL intensity increased by about 47 times. The mechanism of sensing assay has been discussed. In addition, the TPPL assay was highly selective to dopamine and it can distinguish from uric acid, ascorbic acid and metal ions.

Improved host–guest electrochemical sensing of dopamine in the presence of ascorbic and uric acids in a β-cyclodextrin/Nafion®/polymer nanocomposite

2014 ◽  
Vol 6 (15) ◽  
pp. 5962-5971 ◽  
Author(s):  
Nada F. Atta ◽  
Ahmed Galal ◽  
Shimaa M. Ali ◽  
Dalia M. El-Said
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Gold Electrode ◽  
Polymer Nanocomposite ◽  
Electrochemical Sensing ◽  
Voltammetric Method

A voltammetric method based on a combination of β-cyclodextrin, Nafion® and a gold electrode modified with poly(3,4-ethylene-dioxythiophene) has been successfully developed for the determination of dopamine in the presence of ascorbic acid or uric acid.

Highly Selective Electrochemical Sensing of Dopamine, Xanthine, Ascorbic Acid and Uric Acid Using a Carbon Fiber Paper

2020 ◽  
Vol 20 (19) ◽  
pp. 11707-11712
Author(s):  
Jaligam Murali Mohan ◽  
Khairunnisa Amreen ◽  
Arshad Javed ◽  
Satish Kumar Dubey ◽  
Sanket Goel
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Carbon Fiber ◽  
Electrochemical Sensing ◽  
Carbon Fiber Paper
Sign in / Sign up

Export Citation Format

Share Document