Array-Based Electrical Detection of DNA with Nanoparticle Probes*
This chapter reports a DNA array detection method in which the binding of oligonucleotides functionalized with gold nanoparticles leads to conductivity changes associated with target-probe binding events. A major challenge in the area of DNA detection is the development of methods that do not rely on polymerase chain reaction (PCR) or comparable target-amplification systems that require additional instrumentation and reagents that are not ideal for point-of-care or field use. Another restrictive requirement of most DNA detection systems, regardless of their need for PCR, is a thermal-stringency wash to differentiate target strands from ones with mismatches and thus achieve desired analyte selectivity. The chapter presents a conductivity-based DNA detection method utilizing oligonucleotide-functionalized gold nanoparticles that provides an alternative to existing detection methods and presents a straightforward approach to high-sensitivity and -selectivity, multiplexed detection of DNA.