Electronic Detection of Lectins Using Carbohydrate-Functionalized Nanostructures: Graphene versus Carbon Nanotubes

• Published in: ACS nano 2012-01, Vol.6 (1), p.760-770
• Main Authors: Chen, Yanan, Vedala, Harindra, Kotchey, Gregg P, Audfray, Aymeric, Cecioni, Samy, Imberty, Anne, Vidal, Sébastien, Star, Alexander
• Format: Article
• Language: English
• Subjects: Biosensing Techniques - instrumentation; Carbohydrates; Carbohydrates - chemistry; Carbon; Chemical Sciences; Conductometry - instrumentation; Devices; Electronics; Equipment Design; Equipment Failure Analysis; Graphene; Graphite - chemistry; Lectins; Lectins - analysis; Lectins - chemistry; Nanostructure; Nanotubes, Carbon - chemistry; Nanotubes, Carbon - ultrastructure; Organic chemistry; Single wall carbon nanotubes; Titration
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn2042384

Here we investigated the interactions between lectins and carbohydrates using field-effect transistor (FET) devices comprised of chemically converted graphene (CCG) and single-walled carbon nanotubes (SWNTs). Pyrene- and porphyrin-based glycoconjugates were functionalized noncovalently on the surface of CCG-FET and SWNT-FET devices, which were then treated with 2 μM nonspecific and specific lectins. In particular, three different lectins (PA-IL, PA-IIL, and ConA) and three carbohydrate epitopes (galactose, fucose, and mannose) were tested. The responses of 36 different devices were compared and rationalized using computer-aided models of carbon nanostructure/glycoconjugate interactions. Glycoconjugate surface coverage in addition to one-dimensional structures of SWNTs resulted in optimal lectin detection. Additionally, lectin titration data of SWNT- and CCG-based biosensors were used to calculate lectin dissociation constants (K d) and compare them to the values obtained from the isothermal titration microcalorimetry technique.