New Electrochemical (Bio)sensing Strategies Based on the Use of Dispersed Carbon Nanotubes.

GUSTAVO A. RIVAS; N. F. FERREYRA; M. C. RODRÍGUEZ; M. DOLORES RUBIANES; M. LAURA PEDANO; G. L. LUQUE; F. A. GUTIERREZ; P.R. DALMASSO; A. GASNIER; E. N. PRIMO; Y. JALIT,; F. N. COMBA; M. V. BRACAMONTE

Nuremberg

Conferencia; 14th International Meeting in Chemical Sensors; 2012

IMCS 2012

New Electrochemical (Bio)sensing Strategies Based on the Use of Dispersed Carbon Nanotubes G.A. Rivas, N.F. Ferreyra, M.C. Rodríguez, M.D. Rubianes, M.L. Pedano, G.L. Luque, F.A. Gutierrez, P.R. Dalmasso, A. Gasnier, E.N. Primo, Y. Jalit, F.N. Comba, M.V. Bracamonte INFIQC. Departamento de Fisicoquímica. Facultad de Ciencias Químicas. Universidad Nacional de Córdoba. Ciudad Universitaria. 5000 Córdoba. Argentina. grivas@fcq.unc.edu.ar Abstract: Multi-walled carbon nanotubes (MWCNTs) dispersed in different polyelectrolytes were used to develop electrochemical (bio)sensors by drop-coating of glassy carbon electrodes (GCEs). MWCNTs dispersed in polyhistidine were used for the quantification of uric acid or dopamine in the presence of large excess of ascorbic acid, and as platform to build glucose biosensors by self-assembling of glucose oxidase (GOx). The strong interaction of calf thymus-double stranded DNA (dsDNA) with the walls of bamboo-MWCNTs allowed us to obtain stable dispersions and modified GCEsfor sensitive dopamine sensing. The usefulness of GOx to disperse MWCNTs was also demonstrated. The enzyme not only disperses MWCNTs in a very efficient way, but also gives to them excellent biorecognition properties and allows to use it as platform for further immobilization of dsDNA. MWCNTs dispersed in polyethylenimine allowed the development of stable and robust electrochemical sensors for dopamine in complex mixtures and dsDNA through the surface-complex formation. In summary, the analytical performance of the (bio)sensors obtained by modification with CNT dispersions are the result of the combination of the efficiency in the dispersion of MWCNTs and the properties that the dispersing agent provide to them. Key words: carbon nanotubes dispersion, glassy carbon electrodes, electrochemical (bio)sensors, biopolymers, bioanalytes DOI 10.5162/IMCS2012/3.1.4