A ratiometric fluorescent probe for the detection of biological thiols based on a new supramolecular design.

A new ratiometric fluorescent probe is designed and prepared based on the concept of supramolecular encapsulation and dye competition. This supramolecular probe is based on two commercially-available dyes, one common guest and a simple-to-synthesize host. Fluorescence spectroscopy confirms that the supramolecular probe is capable of detecting thiols quantitatively with a broad linear region in phosphate buffered saline or fetal bovine serum. Mechanistic study shows a reaction between thiol specie and the guest to alter the distribution of encapsulated dyes. The supramolecular probes are demonstrated to quantitatively detect extracellular biological thiols by plate reader, which shows it keeps its effectiveness in complex buffered systems.