USING SMALL MOLECULES TO TURN AN RNA APTAMER INTO SENSORS FOR INORGANIC TARGETS WITHOUT IN VITRO SELECTION

Abstract

Aptamers are structured nucleic acid sequences that selectively bind a molecular target with high affinity. Aptamer sequences can be found in nature as gene regulation elements located in the untranslated regions of mRNAs,1 or discovered in the laboratory by in vitro selection (also known as SELEX: systematic evolution of ligands by exponential enrichment) from a random pool of nucleic acids.2,3 Some in vitroselected aptamers can bind and increase the fluorescence quantum yield (FF) of fluorogenic smallmolecule ligands that are otherwise poorly fluorescent in their unbound state.4,5 These aptamers, often referred to as fluorescent light-up aptamers (FLAPs),6 have attracted significant attention due to their potential for biosensing.7–10