Transforming β-cyclodextrin into a non-conventional luminophore via H2O2 oxidation and its application in detection of tetracyclines

Background

The detection of tetracyclines (TCs) has been needed due to their irreversible damage to the environment and human health.

Methods

A novel non-conventional luminophore was synthesized by oxidizing β-cyclodextrin (β-CD) with H₂O₂. The oxidized β-CD (β-CD_ox) has clustering-triggered emission (CTE) property, and exhibits blue fluorescence emission in solid powder and solution. The β-CD_ox and Eu³⁺ ions were simply mixed to fabricate a ratio fluorescence probe for detection of TC, OTC and DOX. In the presence of TCs, the red fluorescence signal of Eu³⁺ was significantly amplified via the inclusion interaction of β-CD_ox and the TCs-induced antenna effect, while the blue emission of β-CD_ox was reduced, allowing the ratio probe to reliably recognize TCs.

Findings

Under the optimized conditions, the ratio of I₆₁₄/I₄₃₀ of the developed probe displayed wide linear ranges of 1.0–30.0 µM, 1.0–30.0 µM and 1.0–40.0 µM for TC, OTC and DOX, respectively, and the limits of detection for TC, OTC and DOX were 0.25 µM, 0.23 µM and 0.48 µM, respectively. In addition, the probe was successfully applied to detect TCs in water samples. Importantly, this study has developed non-conventional luminophores-based ratio fluorescence probe, and has expanded the potential application fields of non-conventional luminophores.