Sensitive detection of ozone by a practical resorufin-based spectroscopic probe with extremely low background signal

Ozone (O-3) has attracted much attention because of its key role in human health and disease, and its detection is of great importance for various biochemical studies as well as environmental evaluation. Here we develop a simple and practical spectroscopic off-on O-3 probe based on resorufin and the specific reaction of but-3-enyl with O-3. The probe shows an extremely low background spectroscopic signal, but reacts with O-3 producing a distinct color and fluorescence change. The detection limit of the probe for O-3 is 5.9 nM, which corresponds to an ozone concentration of 0.056 mg m(-3) in air in this study and is lower than the international ambient air quality standard of 0.1 mg m(-3). More importantly, the proposed probe is worth popularizing, and its applicability has been successfully demonstrated on both the determination of O-3 in real ambient air samples and the imaging of O-3 in biological cells.