Carbon Nanotubes With Different Orientations for Electrochemical Biodevices

Abstract

Abstract-Carbon nanotubes (CNTs) improve the sensitivity of electrochemical biosensors. An optimized CNT/trasducer integration is required to realize accurate devices. The nanotube orientation on the sensor electrode is a key parameter. The role of the sidewalls and the tips in the electroactivity of the nanosensor is presently investigated in the literature. In addition, nanotube hydrophobicity is a drawback for biosensing purposes. Indeed, samples are always in water conditions and the integration biomacromolecules-CNTs are often required. In this paper, a comparison of CNTs with and without exposed walls before and after an acid treatment is proposed. It is done by using contact angle measurements and electrochemical measurements of the electroactive compound potassium ferricyanide. Finally, the electrochemistry of two biomolecules is investigated with those nanostructures more suitable for biodetection.Index Terms-Chemical vapor deposition, cyclic voltammetry, electrochemical biosensors, etoposide, hydrogen peroxide, multiwalled carbon nanotubes, potassium ferricyanide, wettability.

Multiwalled Carbon Nanotubes for Amperometric Array-Based Biosensors

“…Interestingly, the introduction of wall defects improves the detection of hydrogen peroxide. Indeed, sensitivity goes from 28.8 ± 0.1 µA/(mM cm 2 ) to 59.2 ± 0.4 µA/(mM cm 2 ) when randomly oriented nanotubes are treated [46,47].…”