Fluorescence detection of phenylethylamine based on Cucurbit[7]uril supramolecular assemblies

Phenethylamine (PEA) is a novel psychoactive substance that can cause agitation and hallucinations, posing a threat to human health. In this study, a N1@Q[7] supramolecular assembly with a robust fluorescent probe effect was prepared through the supramolecular self-assembly of cucurbit[7]uril (Q[7]) and a bromophenylpyridine derivative (N1).

In this supramolecular assembly, the isoquinoline moiety of N1 entered the cavity of Q[7], while the 4,4-bromophenylpyridyl moiety remained outside, forming a 1:1 inclusion complex. It was found that the addition of other amines did not significantly affect the fluorescence of the assembly, but the addition of PEA caused a notable decrease in fluorescence intensity and a red shift. N1@Q[7] demonstrated sensitive specificity and high selectivity to PEA. The principle is that PEA molecules, N1 molecules, and Q[7] form a synergistic ternary system. Based on this, the detection of PEA in real urine samples by N1@Q[7] was simulated.

The probe exhibited high selectivity in the presence of major components of real urine and enabled visual detection of PEA through fluorescence color change at different concentrations. This study provides a new fluorescent probe method for the detection of drugs and their metabolites.