Application of an Imprint‐and‐Report Sensor Array for Detection of the Dietary Metabolite Trimethylamine N‐Oxide and Its Precursors in Complex Mixtures

Trimethylamine N‐oxide (TMAO) is produced in the gut via metabolism of dietary betaine, choline, and carnitine, and elevated TMAO in plasma is associated with adverse health effects, including cardiovascular events. Currently, we lack high throughput methods for sensing these metabolites and detecting high TMAO. Thus, we have adapted our previously described “imprint‐and‐report” fluorescent sensing method using dynamic combinatorial libraries (DCLs) to create a sensor array for these four metabolites that functions at physiologically relevant concentrations. Templation of DCLs with dye and subsequent addition of analytes generates a fluorescent fingerprint for each metabolite and allows for differentiation via principal component analysis (PCA). Furthermore, we demonstrate that this system can be used to characterize mixtures of the metabolites in both buffer and human plasma samples. Using three to six DCLs, we can distinguish between plasma samples with healthy and elevated levels of TMAO. Several dynamic combinatorial libraries (DCLs) imprinted with a fluorophore were used as sensors to differentially detect four dietary metabolites (betaine, carnitine, choline, and TMAO) in a high‐throughput manner. The method was successful in creating sensor arrays for the analytes at several concentrations, as well as differentiating human plasma samples with elevated TMAO from those with healthy TMAO levels.