Wang, J.Cai, X. H.Fernandes, JRGrant, D. H.Ozsoz, M.2014-05-202014-05-201997-10-01Analytical Chemistry. Washington: Amer Chemical Soc, v. 69, n. 19, p. 4056-4059, 1997.0003-2700http://hdl.handle.net/11449/39131Substantial improvements in the selectivity of electrochemical measurements of trace nucleic adds 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.4056-4059engArtigo10.1021/ac9704319WOS:A1997XX93300033Acesso restrito8540599256820672