Array-Based Electrical Detection of DNA with Nanoparticle Probes
So-Jung Park,
T. Andrew Taton,*
Chad A. Mirkin
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 ~ 100,000:1.
Department of Chemistry and Institute for Nanotechnology,
Northwestern University, Evanston, IL 60208, USA.
*
Present address: Department of Chemistry, University of
Minnesota, Minneapolis, MN 55455, USA.
To whom correspondence should be addressed. E-mail:
camirkin{at}chem.northwestern.edu
