Identification of a DNA aptamer for the detection of sucralose in environmental water samples (928.4)

Sucralose and many other non‐metabolizable food additives, drugs, and consumer personal care products are accumulating to detectable levels in our environment. Traditional analytical instrumentation or antibody‐based ELISA assays can quantitatively assess their presence and have been used to report detectable levels of sucralose in Lake Erie. Aptamers are DNA or RNA based molecules that adopt a specific structure that allows for a characteristic function, often the binding of a small molecule. Biosensors based on aptamer sequences thus provide a unique platform for detection of small molecules, generating a response to analyte through a binding‐specific conformational change. While aptamers have been developed for many target ligands, none exist for sucralose. SELEX (systematic evolution of ligands by exponential enrichment) is a methodology useful for selecting “winning” sequences ‐ the ability to adopt a shape that binds a target molecule ‐ from a library of possible sequences. The process involves several steps that ultimately separate and enrich the population of DNAs with sequences having a high affinity for sucralose. FLU‐MAG SELEX uses two specific modifications to traditional SELEX. Magnetic bead technology (“MAG”) will facilitate separation of mixtures of solutions while fluorescently labeled primers (“FLU”) will allow for the quantitative monitoring of DNAs as SELEX proceeds. Winning sequences can then be modified into structure‐switching biosensors capable of selective and sensitive detection of sucralose from environmental samples.