Advances in the development of Cu(I) complexes as optical oxygen-sensitive probes

Oxygen sensing comprises an emerging technique that is being used in a variety of scientific and technological fields, ranging from medicine to life science. How to detect and identify oxygen quickly and accurately has become an important topic. The optical oxygen sensing technique using luminescent probes has a variety of features that make it capable of detecting molecular oxygen content (e.g. high selectivity, high sensitivity, excellent reversibility, immediate and non-invasive detection). As a suitable non-precious metal oxygen-sensitive probe, the Cu(I) complex is considered to be a promising substitute for traditional precious metal complexes. This review summarizes the results of the studies that have been conducted in the development and design of luminescent Cu(I) complexes, along with their photophysical characteristics related to oxygen sensing. Representative examples are chosen for discussion. In addition, the challenges and future directions for Cu(I) complexes as sensing materials are also presented.