Search PubMed⌕ Search

PubMed · 14580570

Atomic force bio-analytics.

Abstract

The atomic force microscope (AFM) allows biomolecules to be observed and manipulated under native conditions. It operates in buffer solution, produces molecular images with outstanding signal-to-noise ratio, and addresses single molecules. Progress in sample preparation and instrumentation has led to topographs that reveal sub-nanometer details and surface dynamics of biomolecules. Antibodies or oligonucleotides immobilized on cantilevers induce bending upon binding of the cognate biomolecule, allowing sub-picomolar concentrations to be measured. Biomolecules tethered between support and retracting AFM-tip produce force extension curves that reflect the mechanical stability of secondary structure elements. Furthermore, multifunctional tips may activate single molecules to observe them at work. In all cases, the cantilever is critical: its mechanical properties dictate the force-sensitivity and the scanning speed.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P L T M Frederix, T Akiyama, U Staufer, Ch Gerber, D Fotiadis, D J Müller, A Engel. 2003. Atomic force bio-analytics.. https://doi.org/10.1016/j.cbpa.2003.08.010

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Ultralong single-wall carbon nanotubes.

Since the discovery of carbon nanotubes in 1991 by Iijima, there has been great interest in creating long, continuous nanotubes for applications where their properties coupled with extended lengths will enable new technology developments. For example, ultralong nanotubes can be spun into fibres that are more than an order of magnitude stronger than any current structural material, allowing revolutionary advances in lightweight, high-strength applications. Long metallic nanotubes will enable new types of micro-electromechanical systems such as micro-electric motors, and can also act as a nanoconducting cable for wiring micro-electronic devices. Here we report the synthesis of 4-cm-long individual single-wall carbon nanotubes (SWNTs) at a high growth rate of 11 microm s(-1) by catalytic chemical vapour deposition. Our results suggest the possibility of growing SWNTs continuously without any apparent length limitation.

Microscopy, Atomic Force↗

Poly(L-lysine)-mediated immobilisation of oligonucleotides on carboxy-rich polymer surfaces.

The immobilisation efficiency of the complexes of oligonucleotide/poly(L-lysine) on two polymeric carboxy-rich surfaces, i.e. poly(styrene/maleic acid) (PSMA) and poly(styrene/maleic anhydride) (PSMAA), has been investigated using X-ray photoelectron spectroscopy, atomic force microscopy (AFM) and fluorescence-based measurements of DNA attachment. A molecularly thin layer of either electrostatically or covalently (via amide bond) bound poly(L-lysine) allows the 'switching' from COOH-based to NH(2)-based surface functionality. The results indicate that approximately 54-57% and 55-62% of the applied oligonucleotides bind to polymeric surfaces via the route of electrostatic adsorption of poly(L-lysine) and covalent bonding of poly(L-lysine), respectively. This system can be applied conveniently for the detection of nucleic acids in both disposable and reusable biosensors.

Microscopy, Atomic Force↗