Peptide Nucleic Acid Probes for Sequence-Specific DNA Biosensors

TLDR

Surface‑attached peptide nucleic acids retain efficient hybridization and provide higher sensitivity, specificity, faster binding, lower ionic dependence, and shorter probe lengths than DNA counterparts. The study discusses the new capabilities and opportunities enabled by using PNA surface probes for sequence‑specific DNA biosensing. These properties are demonstrated via electrochemical detection of hybridization with a Co(phen)₃³⁺ redox indicator on a carbon paste electrode.

Abstract

Surface-attached peptide nucleic acids (PNA) are shown to retain their unique and efficient hybridization properties, reported in solution studies. PNA recognition layers thus offer significant advantages for sequence-specific DNA biosensors, compared to their DNA counterparts. These advantages include significantly higher sensitivity and specificity (including greater discrimination against single-base mismatches), faster hybridization at room and elevated temperatures, minimal dependence on ionic strength, and use of shorter (10−15-mer) probes. Such unique properties and advantages are illustrated in connection with electrochemical detection of the hybridization event using the Co(phen)33+ redox indicator and a carbon paste electrode transducer. The new capabilities and opportunities afforded by the use of PNA surface probes are discussed.