Interfacing of microbial cells with nanoparticles: Simple and cost-effective preparation of a highly sensitive microbial ethanol biosensor

Jana Šefcovicová, Jaroslav Filip, Jan Tkac

Department of Glycobiotechnology, Center for Glycomics, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovakia

Abstract

Various types of carbon nanoparticles were directly mixed with microbial cells of Gluconobacter oxydans within a 3-D bionanocomposite in order to prepare a highly sensitive ethanol biosensor with a short response time. From all carbonaceous nanomaterials tested, single- or multi-walled carbon nanotubes provided the highest sensitivity of detection (117-121 μA cm^-2mM^-1, but from a practical point of view, Ketjen black 300 and 600 provide very low detection limit (2-6 μM) and high sensitivity for the ethanol analysis (84-88 cm^-2mM^-1) with a short response time (14-33 s). Moreover, the price of Ketjen black is a few orders of magnitude lower compared to that of carbon nanotubes. Finally, the study showed that the morphology of nanoparticles rather than their surface modification is the key element in achieving high sensitivity of ethanol detection.

Keywords: Gluconobacter oxydans; biosensor; ethanol; nanoparticles; carbon nanotubes