ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Electrochemical nanostructured biosensors: carbon nanotubes versus conductive and semi-conductive nanoparticles

Nima Aliakbarinodehi, Irene Taurino, Jagdale Pravin, Alberto Tagliaferro, Gianluca Piccinini, Giovanni De Micheli, and Sandro Carrara

Integrated Systems Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), Route Cantonale, 1015 Lausanne, Switzerland

E-mail: Nima.aliakbarinodehi@epfl.ch

Abstract: The aim of this work was to demonstrate that various types of nanostructures provide different gains in terms of sensitivity or detection limit albeit providing the same gain in terms of increased area. Commercial screen printed electrodes (SPEs) were functionalized with 100 μg of bismuth oxide nanoparticles (Bi₂O₃ NPs), 13.5 μg of gold nanoparticles (Au NPs), and 4.8 μg of multi-wall carbon nanotubes (MWCNTs) to sense hydrogen peroxide (H₂O₂). The amount of nanomaterials to deposit was calculated using specific surface area (SSA) in order to equalize the additional electroactive surface area. Cyclic voltammetry (CV) experiments revealed oxidation peaks of Bi₂O₃ NPs, Au NPs, and MWCNTs based electrodes at (790 ± 1) mV, (386 ± 1) mV, and (589 ± 1) mV, respectively, and sensitivities evaluated by chronoamperometry (CA) were (74 ± 12) μA mM⁻¹ cm⁻², (129 ± 15) μA mM⁻¹ cm⁻², and (54 ± 2) μA mM⁻¹ cm⁻², respectively. Electrodes functionalized with Au NPs showed better sensing performance and lower redox potential (oxidative peak position) compared with the other two types of nanostructured SPEs. Interestingly, the average size of the tested Au NPs was 4 nm, under the limit of 10 nm where the quantum effects are dominant. The limit of detection (LOD) was (11.1 ± 2.8) μM, (8.0 ± 2.4) μM, and (3.4 ± 0.1) μM for Bi₂O₃ NPs, Au NPs, and for MWCNTs based electrodes, respectively.

Keywords: multi-wall carbon nanotube – cyclic voltammetry – chronoamperometry – hydrogen peroxide – bismuth oxide nanoparticle – gold nanoparticle

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0004

Chemical Papers 69 (1) 134–142 (2015)