Dichlorofluorescein as a peroxidase mimic and its application to glucose detection

Abstract

Herein, we discovered, for the first time, that 2′,7′-dichlorofluorescein (DCF), as a novel peroxidase mimic, can catalyze the oxidation of the classical peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H₂O₂, producing a colour reaction. Although a variety of peroxidase mimics have been actively developed recently, few studies have been focused on the small molecule peroxidase mimics. As a novel peroxidase mimic, DCF was verified to be highly stable, well reproducible and of low cost, exhibiting typical Michaelis–Menten kinetics and a strong affinity towards H₂O₂ and TMB. On the basis of these findings, we further demonstrated the novel use of DCF for easy and simple detection of H₂O₂ and glucose. This type of new small molecule peroxidase mimic is expected to be used in medical clinical diagnosis, and this novel finding not only further confirms the peroxidase activity of small molecules of fluorescein derivatives, but also opens new opportunities to deepen the knowledge of this new class of small molecule enzymes.