title: Electrochemical measurements of oligonucleotides in the presence of chromosomal DNA using membrane-covered carbon electrodes.
abstract: Substantial improvements in the selectivity of electrochemical measurements of trace nucleic acids are obtained by using membrane-covered carbon disk electrodes. Access to the electrode surface can be manipulated via a judicious choice of the membrane molecular weight cutoff (MWCO). The resulting separation step, performed in situ at the electrode surface, adds a new dimension of selectivity based on molecular size to electroanalysis of nucleic acids. Transport properties are evaluated with respect to the oligonucleotide length and membrane MWCO. A highly selective response is observed for synthetic oligonucleotides in the presence of otherwise interfering chromosomal DNAs. Discrimination among oligonucleotides of different lengths is also possible. Short accumulation periods (1-5 min) are sufficient for convenient measurements of low milligram per liter concentrations.
authors.affiliation: Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: X
authors.initials: X
authors.lastname: Cai
authors.forename: J R
authors.initials: JR
authors.lastname: Fernandes
authors.forename: D H
authors.initials: DH
authors.lastname: Grant
authors.forename: M
authors.initials: M
authors.lastname: Ozsoz