title: Enzymatic control of metal deposition as key step for a low-background electrical detection for DNA chips.
abstract: Electrical detection of DNA using nanoparticle labels in combination with metal enhancement represents an interesting alternative to fluorescence readout schemes. This electrical method is hampered by unspecific metal deposition, resulting in a lower sensitivity of the assay. A novel enhancement technique based on an enzymatic process is introduced. This approach enables highly specific metal deposition only at the enzyme label, without the background that is typical in the case of the conventional metal enhancement process of growing nanoparticles. The enzymatic enhancement leads to a significant increase in sensitivity, and the detection of single base mismatches demonstrates the high specificity of the novel enhancement approach.
authors.affiliation: Institute for Physical High Technology, P.O. Box 100239, 07702 Jena, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Möller
authors.forename: Richard D
authors.initials: RD
authors.lastname: Powell
authors.forename: James F
authors.initials: JF
authors.lastname: Hainfeld
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Fritzsche
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D004553:Electric Conductivity; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D008839:Microelectrodes; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D009195:Peroxidase / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*
chemical_list: D012834:Silver; D006046:Gold; D004247:DNA; D009195:Peroxidase