Carbon nanotubes paste electrodes

M. D. RUBIANES; G. A. RIVAS

ELECTROCHEMISTRY COMMUNICATIONS

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2003 vol. 5 p. 689 - 694

1388-2481

The performance ofcarbon nanotubes paste electrodes (CNTPE) prepared by dispersion ofmulti-wall carbon nanotubes (MWNT) within mineral oil is described. The resulting electrode shows an excellent electrocatalytic activity toward ascorbic acid, uric acid, dopamine, 3,4-dihydroxyphenylacetic acid (dopac) and hydrogen peroxide. These properties permit an important decrease in the overvoltage for the oxidation of ascorbic acid (230 mV), uric acid (160 mV) and hydrogen peroxide (300 mV) as well as a dramatic improvement in the reversibility ofthe redox behavior ofdopamine and dopac, in comparison with the classical carbon (graphite) paste electrodes (CPE). The substantial decrease in the overvoltage ofthe hydrogen peroxide reduction (400 mV) associated with a successful incorporation ofglucose oxidase (GOx) into the composite material, allow the development ofa highly selective and sensitive glucose biosensor without using any metal, redox mediator or anti-interference membrane. No interference was observed at )0.100 V even for large excess of ascorbic acid, uric acid and acetaminophen. A linear response up to 30 mM (5.40 g l
1) glucose with a detection limit of0.6 mM (0.11 g l
1) were obtained with the CNTPE modified with 10% w/w GOx. Such an excellent performance of CNTPE toward hydrogen peroxide, represents a very good alternative for developing other enzymatic biosensors)0.100 V even for large excess of ascorbic acid, uric acid and acetaminophen. A linear response up to 30 mM (5.40 g l
1) glucose with a detection limit of0.6 mM (0.11 g l
1) were obtained with the CNTPE modified with 10% w/w GOx. Such an excellent performance of CNTPE toward hydrogen peroxide, represents a very good alternative for developing other enzymatic biosensors
1) glucose with a detection limit of0.6 mM (0.11 g l
1) were obtained with the CNTPE modified with 10% w/w GOx. Such an excellent performance of CNTPE toward hydrogen peroxide, represents a very good alternative for developing other enzymatic biosensors