A New Fluorene–Based Fluorescent Probe for Recognition of Hypochlorite Ions and its Applications

Oxidative stress is a trigger for many diseases and occurs with the unstable hypochlorite (ClO⁻), known as one of the reactive oxygen species (ROS) in organisms. Then, HOCI is acknowledged as an oxidizing species that eliminates a variety of environmental pollutants. Hence, the development of novel methodologies for the selective and precise identification of HOCl/ ClO⁻ is considered to be of utmost importance. In this study, the design, characterization, and applications of a fluorene-based fluorescent probe (FHBP) dependent on the ESIPT mechanism with a "turn-on" response for the sensitive/selective determination of ClO⁻ against other competing samples were reported. The experimental results indicated that the detection limit for ClO⁻could be quantitatively determined by the probe to be 8.2 × 10⁻⁷ M. The binding constant of the probe FHBP with ClO⁻ was computed as 9.75 × 10³ M⁻¹. In addition, the response time of FHBP was appointed to be 30 s, indicating a rapid reaction with ClO⁻. It has also been demonstrated that this probe can be successfully used for the detection of ClO⁻ on filter papers, TLC sheets, cotton swabs, and real samples.