Array-based electrical detection of DNA with nanoparticle probes.
A DNA array detection method is reported in which the binding of oligonucleotides functionalized with gold nanoparticles leads to conductivity changes associated with target-probe binding events. The binding events localize gold nanoparticles in an electrode gap; silver deposition facilitated by these nanoparticles bridges the gap and leads to readily measurable conductivity changes. An unusual salt concentration-dependent hybridization behavior associated with these nanoparticle probes was exploited to achieve selectivity without a thermal-stringency wash. Using this method, we have detected target DNA at concentrations as low as 500 femtomolar with a point mutation selectivity factor of approximately 100,000:1.
Park
So-Jung
SJ
Department of Chemistry and Institute for Nanotechnology, Northwestern University, Evanston, IL 60208, USA.
Taton
T Andrew
TA
Mirkin
Chad A
CA
D000942:Antigens, Bacterial; D001408:Bacillus anthracis / Q000235:genetics / Q000302:isolation & purification*; D001427:Bacterial Toxins / Q000235:genetics; D001431:Bacteriological Techniques; D004269:DNA, Bacterial / Q000032:analysis*; D004553:Electric Conductivity; D004581:Electronics; D006046:Gold; D008839:Microelectrodes; D036103:Nanotechnology; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D015345:Oligonucleotide Probes; D017354:Point Mutation; D012680:Sensitivity and Specificity; D012834:Silver
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D015345:Oligonucleotide Probes; C030325:anthrax toxin; D012834:Silver; D006046:Gold