Nanoelectronic Detection of Lectin-Carbohydrate Interactions Using Carbon Nanotubes

• Published in: Nano letters 2011-01, Vol.11 (1), p.170-175
• Main Authors: Vedala, Harindra, Chen, Yanan, Cecioni, Samy, Imberty, Anne, Vidal, Sébastien, Star, Alexander
• Format: Article
• Language: English
• Subjects: Applied sciences; Bacterial Proteins - metabolism; Biosensing Techniques - instrumentation; Carbohydrate Metabolism; Concanavalin A - metabolism; Cross-disciplinary physics: materials science; rheology; Electronics; Equipment Design; Exact sciences and technology; Glycoconjugates - chemistry; Glycoconjugates - metabolism; Lectins - metabolism; Materials science; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Nanotubes, Carbon - chemistry; Nanotubes, Carbon - ultrastructure; Physics; Protein Binding; Pseudomonas aeruginosa - metabolism; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensitivity and Specificity; Transistors; Transistors, Electronic
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl103286k

We have used single-walled carbon nanotube field-effect transistor (NTFET) devices to probe the interactions between carbohydrates and their recognition proteins called lectins. These interactions are involved in a wide range of biological processes, such as cell−cell recognition, cell−matrix interaction as well as viral and bacterial infections. In our experiments, NTFETs were functionalized noncovalently with porphyrin-based glycoconjugates synthesized using “click” azide−alkyne chemistry, and change in electrical conductance was measured upon specific binding of two bacterial lectins that present different carbohydrate preference, namely PA-IL, PA-IIL from Pseudomonas aeruginosa and a plant lectin Concanavalin A. However, no significant change in the device characteristics was observed when the devices were exposed to other lectins with different specificity. Detection of PA-IL binding to galactosylated NTFETs was highly sensitive (2 nM) with a measured dissociation constant (K d = 6.8 μM) corresponding to literature data. Fluorescence microscopy, atomic force microscopy, UV−vis-NIR spectroscopy, and several control measurements confirmed the NTFET response to selective interactions between carbohydrates and lectins.