1. Enzyme-Coated Carbon Nanotubes as Single-Molecule Biosensors
- Author
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Hendrik A. Heering, Cees Dekker, K. Besteman, Frank G. M. Wiertz, and Jeong-O. Lee
- Subjects
Nanotube ,Materials science ,biology ,Mechanical Engineering ,Conductance ,Substrate (chemistry) ,Bioengineering ,Nanotechnology ,General Chemistry ,Carbon nanotube ,Condensed Matter Physics ,Redox ,law.invention ,law ,biology.protein ,Molecule ,General Materials Science ,Glucose oxidase ,Biosensor - Abstract
We demonstrate the use of individual semiconducting single-wall carbon nanotubes as versatile biosensors. Controlled attachment of the redox enzyme glucose oxidase (GOx) to the nanotube sidewall is achieved through a linking molecule and is found to induce a clear change of the conductance. The enzyme-coated tube is found to act as a pH sensor with large and reversible changes in conductance upon changes in pH. Upon addition of glucose, the substrate of GOx, a steplike response can be monitored in real time, indicating that our sensor is also capable of measuring enzymatic activity at the level of a single nanotube. This first demonstration of nanotube-based biosensors provides a new tool for enzymatic studies and opens the way to biomolecular diagnostics.
- Published
- 2003