Nucleic acid-based fluorescent sensor systems: a review

Nucleic acids have been actively applied to various sensing tools and future biodevices because of their high biocompatibility, as well as their programmable properties and functions. In this review, selected nucleic acid-based fluorescent sensors were introduced as powerful tools for exploring intracellular phenomena. Sensing systems in which readable fluorescence signals can be selectively “turned on” in the presence of target analytes are desired to obtain valuable biological information, including intracellular processes in living cells. In this context, we described the representative fluorescent signal generation mechanisms of the selected nucleic acid-based fluorescent sensors, including molecular beacon and quencher-free linear probes, as well as aptamer- and DNAzyme-based systems. In addition, recent examples of signal amplification systems for detecting small amounts of target analytes under isothermal conditions were highlighted.