Review: The increasing importance of carbon nanotubes and nanostructured conducting polymers in biosensors

The growing need for analytical devices requiring smaller sample volumes, decreased power consumption and improved performance have been driving forces behind the rapid growth in nanomaterials research. Due to their dimensions, nanostructured materials display unique properties not traditionally observed in bulk materials. Characteristics such as increased surface area along with enhanced electrical/optical properties make them suitable for numerous applications such as nanoelectronics, photovoltaics and chemical/biological sensing. In this review we examine the potential that exists to use nanostructured materials for biosensor devices. By incorporating nanomaterials, it is possible to achieve enhanced sensitivity, improved response time and smaller size. Here we report some of the success that has been achieved in this area. Many nanoparticle and nanofibre geometries are particularly relevant, but in this paper we specifically focus on organic nanostructures, reviewing conducting polymer nanostructures and carbon nanotubes

Graphene oxide nanoribbons (GNO), reduced graphene nanoribbons (GNR), and multi-layers of oxidized graphene functionalized with ionic liquids (GO-IL) for assembly of miniaturized electrochemical devices

In this critical review, new nanomaterials based on graphene (GN) are described, especially those used for the assembly of miniaturized electrochemical transducers. In particular, the physicochemical properties and mechanical features of few layers of graphene (FLGs) are described, as is their use for assembly of chemically modified sensors, biosensors, and immunosensors. The FLGs described here were functionalized by chemical treatment in solution, resulting in oxidized and/or reduced surfaces, edges, and sides. The presence of oxygenated functionality strongly affects the electrocatalysis and the electron-transfer properties of several molecular targets, not only in the solid phase (e.g. in field-effect transistors, FETs) but also in liquid matrices (chemically modified electrodes and biosensors). In addition, "green chemistry" reagents, for example ionic liquids (ILs) can be used for exfoliation and intercalation of graphene planes, to obtain stable and homogeneous nanodispersions. The assembled sensors, biosensors, and immunosensors are extremely useful for electrochemical detection of several electro-active targets of importance in food analysis, environmental monitoring, and clinical diagnosis. A detailed description of each analytical application has been given in this critical review and brief remarks on the emerging disciplines of nanomedicine and nanofoods are also discussed