Highly Sensitive Determination of Dopamine Using Osmium/Nafion Modified Disposable Integrated Biosensor

2009 ◽  
Vol 60-61 ◽  
pp. 311-314 ◽  
Author(s):  
Chun Xiu Liu ◽  
Hong Min Liu ◽  
Qing De Yang ◽  
Nan Sen Lin ◽  
Yi Lin Song ◽  
...  

A biosensor based on gold electrode modified by Pt nanaoparticles/Osmium redox polymer/Nafion trilayer film was fabricated and used for selective and sensitive determination of dopamine. The biosensor is explored for DA sensing using the cyclic voltammetry (CV), amperometric and differential pulse voltammetric (DPV) methods. The CV anodic peak currents showed a linear range with a correlation coefficient of 0.996, localized in the concentration range 0~192 μM. The differential pulse voltammetric (DPV) peak currents were linear with DA concentration during 2~425 μM with correlation coefficient of 0.99. The biosensor showed high sensitivity of 0.5 nA /nM cm2 and excellent reproducibility with the detection limit of ~10 nM (S/N=3) for the determination of DA. The easy fabrication, low detection limit and high sensitivity of the integrated biosensor making it particularly suitable for the analytical purposes.

2013 ◽  
Vol 830 ◽  
pp. 363-366 ◽  
Author(s):  
Lin Gao ◽  
Bo Yan ◽  
Fang Chen ◽  
Jun Long Yao

Spectrophotometry determination of Al (III) with new color reagent p-Carboxyarsenazo(CAA) was reported, and the chromomeric reaction between CAA and Al (III) was studied. In a buffer medium of pH=4.6 HAc-NaAc, CAA reacts with Al (III) to form a red complex and exhibits an absorption maxima at 614nm; Beer,s law is obeyed for 0.10~0.80 μg/mL of Alumium in color solution, the color reaction exhibited high sensitivity (the apparent molar absorptivity obtained is 1.61×104 L/(mol.cm)), and the absorbance fit linear regression equation is A=0.0105+0.561X(μg/mL), the correlation coefficient is 0.9998, the detection limit of the method is 0.36 μg/L. The results obtained by this method in the determination of environment water samples were rapid, accurate and satisfactorily.


Author(s):  
Neha Thakur ◽  
Debaprasad Mandal ◽  
Tharamani Chikka Nagaiah

An electrochemical non-enzymatic sensor based on NiVP/Pi material was developed for the selective and sensitive determination of glucose. The novel sensor shows ultra-high sensitivity of 6.04 mA μM-1 cm-2 with...


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ali Babaei ◽  
Aliyeh Dehdashti ◽  
Mohammad Afrasiabi

A chemically modified electrode is constructed based on multiwalled carbon nanotube—modified glassy carbon electrode (MWCNTs/GCE). The measurements were carried out by application of differential pulse voltammetry (DPV), cyclic voltammetry (CV), and chronoamperometry (CA) methods. Application of DPV method showed wide linear range of DA from 1 μM to 540 μM and a detection limit of 0.098 μM (S/N=3). The linear range of PAR of 3 μM to 300 μM and a detection limit of 0.15 μM, were obtained. The modified electrode showed electrochemical responses with high sensitivity, high selectivity, and excellent stability for DA and PAR determination at optimal conditions, which makes it a suitable sensor for simultaneous submicromolar detection of DA and PAR in solutions. The analytical performance of this sensor has been evaluated for detection of DA and PAR in human serum, human urine, and pharmaceutical preparation with satisfactory results.


2018 ◽  
Vol 15 (2) ◽  
pp. 6248-6261 ◽  
Author(s):  
Abdul Aziz Ramadan ◽  
Hasna Mandil ◽  
Abdulrahman Shikh-Debes

The effect of gold electrode modified with 2,3-Diaminonaphthalene (GEMDANN) or multi-modified or a mixture 2,3-diaminonaphthalene and o-phenylenediamine -nafion (GEMDAN-OPDAN) on determination of selenium (IV) using differential pulse anodic stripping voltammetric analysis (DPASVA) has been studied. Various parameters (electrolyte, deposition time, pulse duration, pulse amplitude, etc.) are affecting determination of the Se(IV) in HClO4 (0.2 M) at pH 0.22 were examined. Under the optimum conditions, liner calibration graph, Ip=f(CSe4+), were obtained in the concentration ranges of 5x10-8 - 1x10-6 M (3.948 -78.96 ng.mL-1 ) with relative standard deviations (RSD) 4.2% and detection limit 0.056 ng.mL-1, and 1x10-9 -1x10-6 M (0.07896 -78.96 ng.mL-1 ) with relative standard deviations (RSD) 4.9% and detection limit was 0.014 ng.mL-1 on GEMDANN and GEMDAN-OPDAN, respectively. This method showed a good accumulation efficiency for selenium and good resistance to interferences from metal ions as well as those associated with selenium in pharmaceuticals. The results for the determination of Se4+ using GEMDAN-OPDAN (multi-modified) were more sensitive (about 50 times) than that obtained using GEMDANN.


1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.


Author(s):  
Lin He ◽  
Peixia Li ◽  
Kai Li ◽  
Tao Lin ◽  
Jin Luo ◽  
...  

A new cross double point discharge (CrossPD) microplasma was designed as an excitation source to construct a miniaturized optical emission spectrometer with hydride generation (HG) for sample introduction. The CrossPD...


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