Covalently functionalized nanotubes as nanometre- sized probes in chemistry and biology
- 1 July 1998
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature
- Vol. 394 (6688), 52-55
- https://doi.org/10.1038/27873
Abstract
Carbon nanotubes combine a range of properties that make them well suited for use as probe tips in applications such as atomic force microscopy (AFM)1,2,3. Their high aspect ratio, for example, opens up the possibility of probing the deep crevices4 that occur in microelectronic circuits, and the small effective radius of nanotube tips significantly improves the lateral resolution beyond what can be achieved using commercial silicon tips5. Another characteristic feature of nanotubes is their ability to buckle elastically4,6, which makes them very robust while limiting the maximum force that is applied to delicate organic and biological samples. Earlier investigations into the performance of nanotubes as scanning probe microscopy tips have focused on topographical imaging, but a potentially more significant issue is the question of whether nanotubes can be modified to create probes that can sense and manipulate matter at the molecular level7. Here we demonstrate that nanotube tips with the capability of chemical and biological discrimination can be created with acidic functionality and by coupling basic or hydrophobic functionalities or biomolecular probes to the carboxyl groups that are present at the open tip ends. We have used these modified nanotubes as AFM tips to titrate the acid and base groups, to image patterned samples based on molecular interactions, and to measure the binding force between single protein–ligand pairs. As carboxyl groups are readily derivatized by a variety of reactions8, the preparation of a wide range of functionalized nanotube tips should be possible, thus creating molecular probes with potential applications in many areas of chemistry and biology.Keywords
This publication has 25 references indexed in Scilit:
- Chemically-Sensitive Imaging in Tapping Mode by Chemical Force Microscopy: Relationship between Phase Lag and AdhesionLangmuir, 1998
- Carbon Nanotube Tips: High-Resolution Probes for Imaging Biological SystemsJournal of the American Chemical Society, 1998
- Scanning force microscopy under aqueous solutionsCurrent Opinion in Structural Biology, 1997
- CHEMICAL FORCE MICROSCOPYAnnual Review of Materials Science, 1997
- Nanotubes as nanoprobes in scanning probe microscopyNature, 1996
- A nanotube molecular toolNature, 1996
- Crystalline Ropes of Metallic Carbon NanotubesScience, 1996
- Sensitivity of Frictional Forces to pH on a Nanometer Scale: A Lateral Force Microscopy StudyLangmuir, 1995
- Adhesion Forces Between Individual Ligand-Receptor PairsScience, 1994
- X‐Ray Photoelectron and Scanning Auger Electron Spectroscopic Studies of Oxidized Graphite Electrode SurfacesJournal of the Electrochemical Society, 1987