Nanoelectronic detection of lectin-carbohydrate interactions using carbon nanotubes.
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.
Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States.
Harindra
H
Vedala
Yanan
Y
Chen
Samy
S
Cecioni
Anne
A
Imberty
Sébastien
S
Vidal
Alexander
A
Star
D001426:Bacterial Proteins / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation*; D050260:Carbohydrate Metabolism; D003208:Concanavalin A / Q000378:metabolism; D004867:Equipment Design; D006001:Glycoconjugates / Q000737:chemistry* / Q000378:metabolism; D037102:Lectins / Q000378:metabolism*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011485:Protein Binding; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D012680:Sensitivity and Specificity; D014173:Transistors, Electronic
D001426:Bacterial Proteins; D006001:Glycoconjugates; D037102:Lectins; D037742:Nanotubes, Carbon; D003208:Concanavalin A