Chapter 30: Singlet Oxygen Fluorescent Probes

The demand for novel fluorescent probes, proficient for indirectly detecting singlet molecular oxygen, ¹O₂, with a great selectivity and sensitivity is a topic of utmost interest. Approximately from the year 2000, the design and synthesis of dyads containing a chemical trap and a fluorophore has greatly advanced. Before reaction of the probe with ¹O₂, the interaction between the two moieties results in a turned-off state of the fluorescent unit. After reaction, the interaction between the moieties changes and the probe turns fluorescent, allowing detecting and quantifying ¹O₂ in a variety of microenvironments. In this chapter, the most relevant efforts to synthesize fluorescent probes are reviewed and classified according to the mechanisms that govern the interaction between the chemical trap and the fluorophore. Special emphasis is given into covering the performance of these fluorescent probes in sensing ¹O₂ in biological systems. While several attempts have proven successful, further improvement is needed to achieve a suitable fluorescent probe.