LONG-RANGE PROTEIN ELECTRON TRANSFER IN HEME-PROTEIN GOLD NANOPARTICLE HYBRID SYSTEMS

DAIANA CAPDEVILA; DANIEL MURGIDA

Bariloche

Workshop; EULASUR Summer School and Workshop Properties and Applications of Nanomaterials; 2010

Network in Advanced Materials and Nanomaterials of industrial interest between Europe and Latin American Countries of MERCOSUR

A key challenge in the development of electronic biodevices is to improve the efficiency of longrange charge transfer. Recent results hint at the possibility of achieving this goal by manufacturing novel materials which combine nanoparticles with biological Samples showing notable AuNPinduced enhancement of the electron transfer rates. This interesting result added new facets in nanobioeletronics, although the enhancement mechanism is not yet completely understood. Our goal is contributing to eluctidation of such mechanism and optimizing these devices in terms of Raman and electron transfer enhancement for biophysical applications as well as for the rational design of nanobiodevices. Gold nanoparticles stabilized by water soluble thiols ligands were synthesized according to the Brust‐Schiffrin method by two‐step procedure.   A two‐dimensional array of AuNPs was prepared by a crosslinking reaction with a functionalized nanostructured Ag electrode surface. In other to characterize the water soluble AuNPs and nanoelectrodes arrays SEM microscopy measurements were perform showing a 25% coverage of the Ag surface with gold nanoparticles with a 4nm diameter.   Cytochrome c (Cyt c) was electrostatically immobilized on the 2‐D array. The adsorbed protein retains the native structure as judged from the comparison between the Surface Enhance Resonance Raman Spectra (SERRS) of the system and the Resonance Raman    Spectra of the Cyt c in solution. SERRS Spectroelectrochemistry of the immobilized Cyt c indicates that is redox active and presents the same E0 value (8 mV vs. Ag/AgCl) as in  solution.