• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.845-849
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• 2010

A gold nanoparticles modified carbon paste electrode (GN-CPE) has been used for the determination of atenolol (ATN) in drug formulations by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronocoulometric methods. The results revealed that the modified electrode shows an electrocatalytic activity toward the anodic oxidation of atenolol by a marked enhancement in the current response in buffered solution at pH 10.0. The anodic peak potential shifts by -80.0 mV when compared with the potential using bare carbon paste electrde. A linear analytical curve was observed in the range of $1.96\;{\times}\;10^{-6}$ to $9.09\;{\times}\;10^{-4}\;mol\;L^{-1}$. The detection limit for this method is $7.3\;{\times}\;10^{-8}\;mol\;L^{-1}$. The method was then successfully applied to the determination of atenolol in tablets and human urine. The percent recoveries in urine ranged from 92.0 to 110.0%.

• Analytical Science and Technology
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• v.23 no.2
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• pp.165-171
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• 2010

Glucose oxidase ($GOD_{ox}$) immobilized biosensor was fabricated by two methods. In one of the methods, gold nanoparticles (Au-NPs) prepared by ${\gamma}$-irradiation were loaded into the poly(maleic anhydride)-grafted multi-walled carbon nanotube, PMAn-g-MWCNT electrode via physical entrapment. In the other method, the Au-NPs were prepared by electrochemical reduction of Au ions on the surface of PMAn-g-MWCNT electrode and then GODox was immobilized into the Au-NPs. The $GOD_{ox}$ immobilized biosensors were tested for electrocatalytic activities to sense glucose. The sensing range of the biosensor based on the Au-NPs physically modified PMAn-g-MWCNT electrode was from $30\;{\mu}M$ to $100\;{\mu}M$ for the glucose concentration, and the detection limit was $15\;{\mu}M$. Interferences of ascorbic acid and uric acid were below 7.6%. The physically Au deposited PMAn-g-MWCNT paste electrodes appear to be good sensor in detecting glucose.