DNA nanofilm thickness measurement on microarray in air and in liquid using an atomic force microscope.

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RESEARCH PRODUCT

DNA nanofilm thickness measurement on microarray in air and in liquid using an atomic force microscope.

Alain Dereux Rita Meunier-prest Guillaume Legay Moustapha Cherkaoui-malki Eric Finot Norbert Latruffe

subject

MESH : Membranes Artificial MESH: Materials Testing MESH : DNA MESH : Nucleic Acid Conformation Analytical chemistry Tissue Adhesions 02 engineering and technology Microscopy Atomic Force 01 natural sciences Coated Materials Biocompatible MESH: Coated Materials Biocompatible Indentation MESH : Particle Size Microscopy Materials Testing MESH : Coated Materials Biocompatible Electrochemistry MESH : Solutions MESH : Surface Properties Composite material Oligonucleotide Array Sequence Analysis MESH: Microscopy Atomic Force Chemistry Air MESH: DNA General Medicine 021001 nanoscience & nanotechnology Solutions MESH : Oligonucleotide Array Sequence Analysis Membrane MESH: Nucleic Acid Conformation MESH : Air MESH: Membranes Artificial 0210 nano-technology Biotechnology Silicon Surface Properties Biomedical Engineering Biophysics chemistry.chemical_element MESH: Solutions 010402 general chemistry MESH : Materials Testing Adsorption MESH : Adsorption [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology MESH: Particle Size Particle Size Nanoscopic scale [ SDV.BBM ] Life Sciences [q-bio]/Biochemistry Molecular Biology MESH: Surface Properties Membranes Artificial DNA MESH : Microscopy Atomic Force 0104 chemical sciences MESH : Tissue Adhesions MESH: Air MESH: Oligonucleotide Array Sequence Analysis Nucleic Acid Conformation Particle size Adsorption MESH: Tissue Adhesions MESH: Adsorption Biosensor

description

International audience; The measurement of the thickness of DNA films on microarray as a function of the medium (liquid, air) is gaining importance for understanding the signal response of biosensors. Thiol group has been used to attach DNA strands to gold micropads deposited on silicon surface. Atomic force microscopy (AFM) was employed in its height mode to measure the change in the pad thickness and in its force mode to measure the indentation depth of the nanofilm. A good coherence between the height and force modes is observed for the film thickness in air. The adhesion force was found to be an alternative way to measure the surface coverage of the biolayer at nanoscopic scale. However the force analysis (compression, steric and electrostatic) provides baseline information necessary to interpret the AFM height image in liquid. Analysis of the film thickness distribution shows that the height of the DNA strands depends on both the DNA strand length (15-35 base pairs) and the environment (air, liquid). In air, longer strands lay down onto gold surface whereas the charge reversal of gold in liquid causes a repulsion of longer strands, which stand up.

year	journal	country	edition	language
2005-10-15

10.1016/j.bios.2004.12.021 https://hal.archives-ouvertes.fr/hal-00376258/file/LegayBB04.pdf