Advances in Chemistry Research. Volume 64 first focuses on the fluorescence detection or imaging of cupric ions by synthetic fluorescent probes. Major literature reports in the field of small molecules as fluorescent sensors for the detection of Cu2+ ions since 2011 till date are discussed. The authors provide a general overview of different types of click polymerizations and their membrane applications as high-performance polymers, with a special emphasis on the recent developments of Cu AAC click polymerizations in their laboratory in the field of proton exchange membranes. Lastly, the latest achievements and prospects for applying the Cu AAC reaction in the synthesis of biologically active steroids and triterpenoids are discussed. Steroids and triterpenoids are available and promising initial materials for the Cu AAC reaction due to their wide biological activity, structural diversity, and abundance in nature.