title: Carbon-nanotube-modified electrodes for amplified enzyme-based electrical detection of DNA hybridization.
abstract: Carbon-nanotube-modified glassy carbon (CNT/GC) transducers have been developed for enhancing the sensitivity and stability of enzyme-based electrochemical bioassays of DNA hybridization. The amplified signal reflects the interfacial accumulation of phenolic products of the alkaline-phosphatase tracer onto the CNT layer. In particular, chronopotentiometric measurements (following short accumulation periods) offer a substantial enhancement of the response of enzymatically liberated alpha-naphthol. The CNT modifier also leads to a dramatic improvement in the stability of the amperometric response of alpha-naphthol. These advantages of CNT/GC electrodes are illustrated from comparison to unmodified glassy carbon electrodes. Factors influencing the adsorptive accumulation of alpha-naphthol, and the overall performance of the new DNA assay, are assessed and optimized. The attractive performance characteristics of the new multi-amplification electrochemical detection of DNA hybridization are reported in connection to the detection of nucleic acid sequences related to the breast cancer BRCA1 gene.
authors.affiliation: Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA. joewang@nmsu.edu
authors.forename: Joseph
authors.initials: J
authors.lastname: Wang
authors.forename: Abdel-Nasser
authors.initials: AN
authors.lastname: Kawde
authors.forename: M Rasul
authors.initials: MR
authors.lastname: Jan
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017403:In Situ Hybridization / Q000295:instrumentation* / Q000379:methods; D008422:Materials Testing; D008839:Microelectrodes; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D037742:Nanotubes, Carbon; D004247:DNA; D000469:Alkaline Phosphatase