Improved detection of Candida albicans with carbon nanotube field-effect transistors

A biosensor for detecting Candida albicans has been developed to improve the performance characteristics of the Currently available methods. It is based on a field-effect transistor(FET) in which a network of single-walled carbon nanotubes (SWCNTs) acts as the conductor channel. Monoclonal anti-Candida antibodies were adsorbed onto the SWCNT to provide specific binding sites for fungal antigens. Tween 20 at 0.5% was used as a blocking agent to prevent the non-specific binding of other yeasts or proteins. Our FET devices were exposed to increasing concentrations of C albicans and were able to detect at least 50 cfu/mL in only 1 h. The sensor response remained stable for more than 10 days. To evaluate the selectivity of our FET devices, Cryptococcus albidus and Saccharomyces; cerevisiae were tested as potential competing yeasts for C. albicans. The results showed that biosensors based on a carbon nanotube field-effect transistor are useful tools to detect pathogenic yeasts like C. albicans at low concentrations displaying high selectivity. (C) 2008 Elsevier B.V. All rights reserved.