Rational Design of Framework Nucleic Acids for Bioanalytical Applications

With the advent of DNA nanotechnology, nucleic acids have been used building blocks for constructing various DNA nanostructures. As classical and simple DNA nanostructures, framework nucleic acids (FNAs) have attracted enormous attention in the field of biosensing. The sequence-specific self-assembly properties and high programmability of nucleic acids allow FNAs to be incorporated in advanced probe design. In addition, FNAs enable the engineering of surfaces for biosensing (e. g., probe orientation, probe spacing), thereby improving the accessibility of target molecules to the probes arranged on heterogeneous surfaces. Moreover, FNAs offer a universal and promising platform for sensing cellular molecules because of their prominent biocompatibility and cellular permeability. Herein recent advances in FNA-based biosensors are summarized, including electrochemical detection, optical detection, and intracellular sensing. It is hoped that this review will provide guidelines for the design and construction of FNA scaffold-based biosensors.