Electrochemical Preparation of Poly(3,4-Ethylenedioxythiophene) Layers on Gold Microelectrodes for Uric Acid-Sensing Applications

Author(s):  
Mahsa - Motshakeri ◽  
Anthony R. J. Phillips ◽  
Paul A. Kilmartin
2013 ◽  
Vol 543 ◽  
pp. 72-75
Author(s):  
Balakrishnan Karthikeyan ◽  
Marimuthu Murugavelu

The emergence of nanoparticles (NPs) has opened new opportunities in analytical chemistry [. These NPs exhibit different properties and functionalities when compared to monometallic particles. In particular, they show enhanced selectivity and reactivity when used as catalysts and sensors [2-. The NPs have large surface area, high surface free energy, good biocompatibility and suitability, and it has been used in constructing electrochemical biosensors [7, . The fascinating physical and chemical properties of NPs offer excellent prospects for a wide range of bio sensing applications [ . Uric acid (UA) is the principal final product of purine metabolism in the human body [1. It has been shown that extreme abnormalities of UA levels are symptoms of several diseases (e.g. gout, hyper uricaemia and LeschNyhan syndrome)[11,1.In general, electro active UA can be irreversibly oxidized in aqueous solution and the major product is allantoin [1. In continuation of our interest with the bimetal nanoparticle (BNP) sensing here in this study, we employed Ag/Pt BNPs for detecting of UA.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Dina M. Fouad ◽  
Waleed A. El-Said

Epinephrine (EP) is one of the important catecholamine neurotransmitters that play an important role in the mammalian central nervous system. Therefore, it is necessary to determine the change of its concentrations. Nanoporous materials have wide applications that include catalysis, energy storages, environmental pollution control, wastewater treatment, and sensing applications. These unique properties could be attributable to their high surface area, a large pore volume, and uniform pore sizes. A gold nanoporous layer modified gold electrode was prepared and applied for the selective determination of epinephrine neurotransmitter at low concentration in the presence of several other substances including ascorbic acid (AA) and uric acid (UA). The constructed electrode was characterized using scanning electron microscopy and cyclic voltammetry. The resulting electrode showed a selective detection of epinephrine with the interferences of dopamine and uric acid over a wide linear range (from 50 μM to 1 mM). The coverage of gold nanoporous on the surface of gold electrode represents a promising electrochemical sensor with high selectivity and sensitivity.


2021 ◽  
Author(s):  
Misbah Asif ◽  
Hasnain Sajid ◽  
Khurshid Ayub ◽  
Mazhar Amjad Gilani ◽  
Mohammed Salim Akhter ◽  
...  

Abstract Though, the gas sensing applications of graphdiyne have widely reported; however, the biosensing utility of graphdiyne needs to be explored. This study deals with the sensitivity of graphdiyne nanoflake (GDY) towards the uric acid (UA) within the density functional framework. The uric acid is allowed to interact with graphdiyne nanoflake from all the possible orientations. Based on these interacting geometries, the complexes are differentiated with naming i.e., UA1@GDY, UA2@GDY, UA3@GDY and UA4@GDY (Figure 1). The essence of interface interactions of UA on GDY is derived by computing geometric, energetic, electronic and optical properties. The adsorbing affinity of complexes is evaluated at ωB97XD/6-31+G(d,p) level of theory. The stabilities of the complexes are quantified through the interaction energies (Eint) with reasonable accuracy. The calculated Eint of the UA1@GDY, UA2@GDY, UA3@GDY and UA4@GDY complexes are -31.13, -25.87, -20.59 and -16.54 kcal/mol, respectively. In comparison with geometries, it is revealed that the higher stability of complexes is facilitated by π-π stacking. Other energetic analyses including symmetry adopted perturbation theory (SAPT0), noncovalent interaction index (NCI) and quantum theory of atoms in molecule (QTAIM) provided the evidence of dominating dispersion energy in stabilizing the resultant complexes. The HOMO-LUMO energies, NBO charge transfer and UV-vis analysis justify the higher electronic transition in UA1@GDY, plays a role of higher sensitivity of GDY towards the π-stacked geometries over all other possible interaction orientations. The present findings bestow the higher sensitivity of GDY towards uric acid via π-stacking interactions.


2016 ◽  
Vol 45 (9) ◽  
pp. 2458-2493 ◽  
Author(s):  
Adriano Ambrosi ◽  
Chun Kiang Chua ◽  
Naziah Mohamad Latiff ◽  
Adeline Huiling Loo ◽  
Colin Hong An Wong ◽  
...  

The electrochemistry of graphene and its derivatives has been extensively researched in recent years. This extends from the electrochemical preparation methods, the electrocatalytic properties of graphene doped with p-block or d-block elements, the capacitive properties to the electrochemical sensing applications.


2003 ◽  
Vol 2 (1) ◽  
pp. 79
Author(s):  
P PAVLIDIS ◽  
J PARISSIS ◽  
S ANTONOPOULOS ◽  
D POLLATOS ◽  
P KIRIAZOPOULOS ◽  
...  

JAMA ◽  
1966 ◽  
Vol 196 (4) ◽  
pp. 364-365 ◽  
Author(s):  
L. A. Healey
Keyword(s):  

Author(s):  
Sanem Kayhan ◽  
Nazli Gulsoy Kirnap ◽  
Mercan Tastemur

Abstract. Vitamin B12 deficiency may have indirect cardiovascular effects in addition to hematological and neuropsychiatric symptoms. It was shown that the monocyte count-to-high density lipoprotein cholesterol (HDL-C) ratio (MHR) is a novel cardiovascular marker. In this study, the aim was to evaluate whether MHR was high in patients with vitamin B12 deficiency and its relationship with cardiometabolic risk factors. The study included 128 patients diagnosed with vitamin B12 deficiency and 93 healthy controls. Patients with vitamin B12 deficiency had significantly higher systolic blood pressure (SBP), diastolic blood pressure (DBP), MHR, C-reactive protein (CRP) and uric acid levels compared with the controls (median 139 vs 115 mmHg, p < 0.001; 80 vs 70 mmHg, p < 0.001; 14.2 vs 9.5, p < 0.001; 10.2 vs 4 mg/dl p < 0.001; 6.68 vs 4.8 mg/dl, p < 0.001 respectively). The prevalence of left ventricular hypertrophy was higher in vitamin B12 deficiency group (43.8%) than the control group (8.6%) (p < 0.001). In vitamin B12 deficiency group, a positive correlation was detected between MHR and SBP, CRP and uric acid (p < 0.001 r:0.34, p < 0.001 r:0.30, p < 0.001 r:0.5, respectively) and a significant negative correlation was detected between MHR and T-CHOL, LDL, HDL and B12 (p < 0.001 r: −0.39, p < 0.001 r: −0.34, p < 0.001 r: −0.57, p < 0.04 r: −0.17, respectively). MHR was high in vitamin B12 deficiency group, and correlated with the cardiometabolic risk factors in this group, which were SBP, CRP, uric acid and HDL. In conclusion, MRH, which can be easily calculated in clinical practice, can be a useful marker to assess cardiovascular risk in patients with vitamin B12 deficiency.


Sign in / Sign up

Export Citation Format

Share Document