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

A ratiometric fluorescent probe based on thiol-disulfide exchange and indicator displacement is developed for the detection of thiols. [Display omitted] •A new fluorescence spectroscopic analytical method based on commercially-available dye.•A novel design strategy based on a reactive guest and indicator displacement.•A simple probe preparation without the need of laborious synthesis.•A wide linear region of quantitative analysis. 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.