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

Congreso; The 14th International Meeting on Chemical Sensors; 2012

Multi-walled carbon nanotubes (MWCNTs) dispersed in different polyelectrolytes were used todevelop electrochemical (bio)sensors by drop-coating of glassy carbon electrodes (GCEs). MWCNTsdispersed in polyhistidine were used for the quantification of uric acid or dopamine in the presence oflarge excess of ascorbic acid, and as platform to build glucose biosensors by self-assembling ofglucose oxidase (GOx). The strong interaction of calf thymus-double stranded DNA (dsDNA) with thewalls of bamboo-MWCNTs allowed us to obtain stable dispersions and modified GCEsfor sensitivedopamine sensing. The usefulness of GOx to disperse MWCNTs was also demonstrated. The enzymenot only disperses MWCNTs in a very efficient way, but also gives to them excellent biorecognitionproperties and allows to use it as platform for further immobilization of dsDNA. MWCNTs dispersed inpolyethylenimine allowed the development of stable and robust electrochemical sensors for dopaminein complex mixtures and dsDNA through the surface-complex formation. In summary, the analyticalperformance of the (bio)sensors obtained by modification with CNT dispersions are the result of thecombination of the efficiency in the dispersion of MWCNTs and the properties that the dispersingagent provide to them.