Nanomaterials-based microbial sensor for direct electrochemical detection of Streptomyces Spp.

Since development of new methods for rapid and reliable detection of pathogens is urgently needed. CertainStreptomyces species are considered pathogenic as they cause invasive infections. A nanomaterial basedmicrobial sensor for direct determination of Streptomyces's viability was designed. By using a carbonpaste electrode matrix (CPE), the effects of several nanomaterials on the direct detection of the targetorganism's viability were studied. Incorporation of nanomaterials into the electrode matrix produced asignificant improvement of the oxidation current; however, multi-walled carbon nanotubes (MWCNTs, 10%, w/w) exhibited the highest electrocatalytic performance. Generation of oxidation current throughinteraction of viable Streptomyces cells with the electrode surface was dependent on metabolic activity. Consequently, several bioelectrochemical factors, such as type of carbon source, cell viability, sensingtime and scan rate have been optimized. In conclusion, the assay presented here has been utilized formonitoring the growth rate as well as the cell viability. Moreover, the response of Streptomyces to abetalactam antibiotic (meropenem) has been determined which would provide a convenient toxicitymonitoring system that could be applied for diagnostics. (C) 2014 Elsevier B. V. All rights reserved.