Array-based electrical detection

Park S.-J., Taton T.A., Mirkin C.A., Array-based electrical detection of DNA using nanoparticle probes, Science 2002 295 1503-1506. 

SJ. Park, T.A. Taton, and C.A. Mirkin, Array-based electrical detection of DNA with nanoparticle probes. Science 295, 1503—1506 (2002). 

Optical gene chips dense arrays of oligonucleotides have been successfully applied to detect transcriptional profiling and SNP discovery, where massively parallel analysis is required. However, the fluorescence-based readout of these chips involves not only highly precise and expensive instrumentation but also sophisticated numerical algorithms to interpret the data, and therefore these methods have been commonly limited to use in research laboratories. In this way, thin-film arrays of 14, 20, 25, 48 and 64 electrodes have already been fabricated [12,15,39,40,44,48], using lithographic techniques. Readout systems for these arrays based on electrical detection have also been developed. 

A nanogapped microelectrode-based PANI-NF biosensor array was fabricated for ultrasensitive electrical detection of microribonucleic acids (miRNAs) [488]. Deposition of conducting PANI-NFs was carried out by an enzyme-catalyzed method, where the electrostatic interaction between anionic phosphate groups in miRNA and cationic aniline molecules was exploited to guide the formation of the PANI-NFs on the hybridized target miRNA. The conductance of the deposited PANI-NFs was correlated directly to the amount of the hybridized miRNA, with a detection hmit of 5.0 x 10 M. 

The topics discussed in the book include electrochemical detection of DNA hybridization based on latex/gold nanoparticles and nanotubes nanomaterial-based electrochemical DNA detection electrochemical detection of microorganism-based DNA biosensor gold nanoparticle-based electrochemical DNA biosensors electrochemical detection of the aptamer-target interaction nanoparticle-induced catalysis for DNA biosensing basic terms regarding electrochemical DNA (nucleic acids) biosensors screen-printed electrodes for electrochemical DNA detection application of field-effect transistors to label-free electrical DNA biosensor arrays and electrochemical detection of nucleic acids using branched DNA amplifiers. 

Detection of DNA hybridization used in connection with conductometric measurements after labeling with AuNPs has been demonstrated by Mirkin s group [67]. They developed an array based on electrical detection utilizing oligonucleotide functionalized Au NPs and closely spaced interdigitated microelectrodes. The oligonucleotide probe was immobilized in the gap between the two microelectrodes. The hybridization event, thus, localizes Au... 

---