DNA and PNA Probes for DNA Detection in Electroanalytical Systems

There is a strong demand for sensitive DNA assays that are fast, simple to use, and inexpensive. Traditional approaches rely on labeled molecules, for example, fluorescent probes, providing an optical transduction. However, modern electroanalytical approaches have been described since the 1990s, involving electrochemical then transistor-based transductions. In addition to classical DNA probes, initially developed for other purposes, many forms of promising nucleic acid analogs and mimics were also involved in DNA sensors, such as locked nucleic acids (LNAs), peptide nucleic acids (PNAs), and other XNAs. More recently, transduction architectures based on nanometer-sized devices (not only nanoparticles but nanogaps, nanowires, nanopores, etc.) have been described, allowing exceedingly high sensitivities.