Authors: H. Vedala, Y. Chen, A. Star
Affilation: University of Pittsburgh, United States
Pages: 48 - 51
Keywords: biosensors, nanotubes, bacterial detection, field-effect transistors
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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