Peptide nucleic acids (PNA) are new DNA analogs which offer great prom
ise for highly specific DNA biosensors, for use as antisense drugs, or
for various molecular biology applications. This article evaluates th
e interfacial behavior of PNA at carbon paste electrodes, in compariso
n to DNA, While both PNA and DNA oligomers display a strong adsorption
onto the carbon surface, they differ in their interfacial properties
due to differences in charge and structure. Factors influencing the ad
sorption behavior, including the adsorption potential or time, PNA con
centration, coexisting anions and cations, or buffer concentration, ar
e explored. The strong adsorption is exploited for an effective precon
centration step prior to the chronopotentiometric measurement. The res
ulting adsorptive stripping potentiometric protocol offers convenient
quantitation of ng/mL levels of PNA, as desired for future diagnostic,
pharmaceutical and biological applications of these DNA analogs.