Supramolecular Sensors for Opiates and Their Metabolites

The present study
highlights a sensing approach for opiates using
acyclic cucurbituril (aCBs) sensors comprising four glycouril units
terminated on both ends with naphthalene fluorophore walls. The connectivity
between the glycourils and naphthalene rings largely defines the opening
size of the cucurbituril cavity and its diameter. The large hydrophobic
binding cavity is flexible and is able to adapt to guests of various
size and topology. The recognition event between the aCBs and guests
results in modification of the fluorescence of the terminal walls,
a fluorescence response that can be used to sense the drugs of abuse
morphine, heroin, and oxycodone as well as their metabolites. Molecular
dynamics is employed to understand the nature of the binding interactions.
A simple three sensor cross-reactive array enables the determination
of drugs and their metabolites in water with high fidelity and low
error. Quantitative experiments performed in urine using a new three-way
calibration model allows for determination of drugs and their metabolites
using one sensor from a single fluorescence reading.