Probing Protein-Carbohydrate Interactions using Carbon Nanotube Nanodevices for Rapid Bacterial Detection

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In this work, we demonstrate novel nanoelectronics devices based on single-walled carbon nanotube field-effect transistor (NTFET) 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 (Kd = 6.8 μM) corresponding to literature data. Results are validated by conducting various characterization techniques such as Fluorescence microscopy, atomic force microscopy, UV-vis-NIR spectroscopy and control experiments. These results demonstrate a significant advancement in NTFET based electronic devices for detecting complex biological interactions (carbohydrate and protein) for future nanomaterials based sensor applications.

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Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2011: Bio Sensors, Instruments, Medical, Environment and Energy
Published: June 13, 2011
Pages: 48 - 51
Industry sectors: Medical & Biotech | Sensors, MEMS, Electronics
Topics: Chemical, Physical & Bio-Sensors, Diagnostics & Bioimaging
ISBN: 978-1-4398-7138-6