Towards a plastic enzyme nanotransistor responsive to glucose, Preliminary results

A. CALVO; D. GRUMELLI; C. BONAZZOLA; M. G. BELLINO; E. J. CALVO; P. BOZZANO

Valles Calchaquíes, Argentina

Workshop; NSF-CONICET Quilmes Nanoscience Workshops : Electronics witch Molecules and Quantum Dots; 2003

National Science Fundation, CONICET

We have employed a membrane template to prepared gold and polyestirene-sulfonate (PSS) doped polyaniline (PANI-PSS) nanorods. Preliminary results are presented for single Au and PANI-PSS nanorods (300 nm tipical diameter and 10 mm in lenght). Au-PANI composite nanorods were synthezed in a two step filling procedure. The preparation of the nanorods was as follows: Prior to pores filling with Au or PANI/PSS, alumina membranes (Whatman Anodisc 13, 0.2 mm pore size, 13 mm diameter) were first covered with 200 nm Ag deposit by termal evaporation (Edwards Auto 306). These metalized membranes were used at the working electrode in a all teflon electrochemical cell. The pores were filled with Au electrodeposited from gold cyanide solution at costant current to predetermined chrge on the small silver deposited at botton of the pore. In some preliminare experiments Tracketched polycarbonate membranes were also employed (Millipore Isopore 0.2 mm) as template. For composite nanorods, after Au deposition and rinsing with distilled water, PSS doped polyaniline was electrodeposited from 0,5 M anilime in 2 M H2SO4 sulfuric acid and 0,5 M NaHSO4 with dialyzed PSS (10 mg ml-1) at constant potential (0.9 V) until a predetermined charged was reached.             After depesition and filling of the nanopores, the alumina membranes were dissolved in 4 M hydrocloric acid and the resulting nanowires were separed by sonication, after disolution of the Ag end with 4M HNO3. For Au nanowires, effective separation wos achivied by adsorbing mercapto-propanesulfonate on the Au surface. The resulting nanorods could be assembled as nanowire contact between two 10 mm contac Au bands separated by a 10 mm insulating band gap on a pcb, under the asistance of an ac electric-field following the technique described by Mayer and Mallouk.