Dispersion of multi-wall carbon nanotubes in polyhistidine: characterization and analytical applications

DALMASSO PABLO; M. L. PEDANO; G. A. RIVAS

ELSEVIER SCIENCE SA

Año: 2011

p style="LINE-HEIGHT: 200%; MARGIN: 0cm 0cm 0pt" class="MsoNormal">We report for the first time the use of polyhistidine (Polyhis) to efficiently disperse multiwall carbon nanotubes (MWCNTs). The optimum dispersion MWCNT-Polyhis was obtained by sonicating for 30 min 1.0 mg/mL MWCNTs in 0.25 mg/mL Polyhis solution prepared in 75:25 v/v ethanol/0.200 M acetate buffer solution pH 5.00. The dispersion was characterized by scanning electron microscopy, and by cyclic voltammetry and amperometry using ascorbic acid as redox marker. The modification of glassy carbon electrodes with MWCNT-Polyhis produces a drastic decrease in the overvoltage for the oxidation of ascorbic acid (580 mV) at variance with the response observed at glassy carbon electrodes modified just with Polyhis, where the charge transfer is more difficult due to the blocking effect of the polymer. The reproducibili