New Electrochemical (Bio)sensing Strategies Based on the

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

Nürnberg

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

Department of Functional Materials, University of Bayreuth, Bayreuth, Germany.

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.