DNA for Non-nucleic Acid Sensing

Abstract

The structure of DNA, encoded on four bases, allows to generate a considerable number of unique markers, even considering very short sequences composed of n nucleotides leading to 4 n different combinations. The possibility of synthesizing DNA sequences in vitro at low cost and in large quantities, coupled with well-known strategies of strand functionalization with groups having optical, magnetic or redox properties, allows to consider DNA not simply as a tool for detection of target nucleotide sequences but as versatile label in many biomolecular recognition event transduction schemes. This ability is strongly enhanced by modern DNA amplification approaches. Furthermore, iterative selection methods (SELEX) have achieved a high level of performance, reliability and sophistication, enabling the use of short DNA sequences also as selective binding element for the detection of an increasing number of analytes ranging from proteins to small organic molecules, such as pollutants and endocrine disruptors. This chapter highlights the progress made in the areas of analytical sciences through the use of nucleic acid sequences that act either only as an amplifiable label or both as a recognition element and as a marker.