A novel cucurbit[8]uril-based fluorescent probe for the detection of phenethylamine in urine

Beta-phenylethylamine (PEA), is known to scientists as the "mood hormone", posing a threat to human health. In this study, an "on-off-on" supramolecular fluorescent probe was developed for the detection of PEA. The probe, namely PDT@2Q[8], was assembled from cucurbit[8]uril (Q[8]) and a coumarin derivative (PDT) via a host-guest interaction in a 2:1 binding ratio.

The solution fluorescence was turned on again when PEA was added to PDT@2Q[8] in aqueous solution. The intensity of the fluorescence of the solution returned to blue following quenching, and the intensity of the fluorescence of the solution correlated with the concentration of PEA at 395 nm in a linear manner. The probes detection limit for PEA was 3.08 μM over the linear range 0.5-3 × 10^-4 M. The probe was used for the detection of PEA in urine, and the detection limit for PEA was 1.34 μM over the linear range of 0.4-1.6 × 10^-4 M.

As an "on-off-on" fluorescence-opening cucurbit[n]urils-based fluorescent probe, PDT@2Q[8] is not only simple to prepare, and of low-cost, but also exhibits significant fluorescence before and after the addition of PEA, with a fast response time and high sensitivity. This study provides a new fluorescent probe method for the detection of Beta-phenylethylamine (PEA).