Articles généraux

Jong-in Hahm and Charles M. Lieber, "Direct Ultrasensitive Electrical Detection of DNA and DNA Sequence Variations Using Nanowire Nanosensors"

The development of electrically addressable, label-free detectors for DNA and other biological macromolecules has the potential to impact basic biological research as well as screening in medical and bioterrorism applications. Here we report two-terminal silicon nanowire electronic devices that function as ultrasensitive and selective detectors of DNA. The surfaces of the silicon nanowire devices were modified with peptide nucleic acid receptors designed to recognize wild type versus the ¢F508 mutation site in the cystic fibrosis transmembrane receptor gene. Conductance measurements made while sequentially introducing wild type or mutant DNA samples exhibit a time-dependent conductance increase consistent with the PNA-DNA hybridization and enabled identification of fully complementary versus mismatched DNA samples. Concentration-dependent measurements show that detection can be carried out to at least the tens of femtomolar range. This nanowire-based approach represents a step forward for direct, label-free DNA detection with extreme sensitivity and good selectivity, and could provide a pathway to integrated, high-throughput, multiplexed DNA detection for genetic screening and biothreat detection.

F. Patolsky, C.M. Lieber, "Nanowire, Nanosensors"

 

A. Poghossian, A. Cherstvy, S. Ingebrandt, A. Offenhausser, M.J. Schoning, "Possibilities and limitations of label-free detection of DNA hybridization with field-effect-based devices"

A critical evaluation of the possibilities and limitations of the label-free detection of deoxyribonucleic acid (DNA) hybridization by means of field-effect-based devices is discussed. A new DNA-detection method is introduced, which utilizes an ion-sensitive field-effect device as transducer. The upon the DNA hybridization induced redistribution of the ion concentration within the intermolecular spaces and/or the alteration of the ion sensitivity of the device is proposed as detection mechanism. The theoretical calculations predict a substantial change in the average ion concentration within the intermolecular spaces induced upon hybridization that are enough to obtain a detectable sensor signal.

renseignement sur la technique PamGene

Voici les quelques documents électroniques en ma possession sur le technologie Pamgene (hybridation de protéines ou d'acides nucléiques sur un dispositif tridimentionnel nanoporeux de Al2O3): la fonctionalisation biologique - accrochage des ADN ou anticorps ou antigène- est apparemment facile : elle se fait en "pompant" à plusieurs reprises - je crois 4 à 5 fois - les réactifs "au travers" de ce dispositif par mouvement de va-et-vient). Le site de pamgene est intréressant: http://www.pamgene.com/ : allez voir dans TECHNOLOGY : fichier explicatif audio pas mal fait