Ratiometric colorimetric and fluorometric dual-sensing system based on anthracene derivatives for the determination of ClO− and total antioxidant capacity

Abstract

In this work, a fluorescent small molecule based on 9,10-distyryl anthracene (DSA-2OH) with AIE properties was prepared. DSA-2OH can be oxidized by hypochlorite (ClO⁻) to oxidized DSA (ODSA), which can be re-reduced to DSA-2OH by reducing agents. This oxidation–reduction process is accompanied by changes in fluorescence intensity and absorption wavelength. Based on this principle, a colorimetric/fluorometric dual-mode assay for the determination of ClO⁻ and the total antioxidant capacity (TAC) are realized. In contrast to the colorimetric method, the fluorometric method has better detection effect. The fluorometric detection method can detect ClO⁻ and ascorbic acid (AA) in a three-order-of-magnitude concentration range (0.1–20 μM and 0.2–30 μM). The detection limits (LOD) of fluorometric methods for ClO⁻ and AA are 44 nM and 55 nM, respectively. The two methods can mutually validate each other to improve detection accuracy. The proposed assay can detect TAC in drinks such as orange juice, kiwi juice and drinking water with recoveries ranging from 95 % to 105 %, which can help us to make healthier and more sensible dietary choices.