Activatable Photoacoustic/Near-Infrared Probes for the Detection of Copper Ions of Cardiovascular Disease In Vivo and in Urine

Copper ions, implicated in processes such as oxidative stress and inflammation, are believed to play a crucial role in cardiovascular disease, a prevalent and deadly disease. Despite this, current diagnostic methods fail to detect early stage cardiovascular disease or track copper ion accumulation, limiting our understanding of the disease's progression. Therefore, the development of noninvasive techniques to image copper ions in cardiovascular disease is urgently needed to enhance diagnostic precision and therapeutic strategies. In this study, we report the successful synthesis and application of a copper ion-activated photoacoustic probe, <b>CS-Cu</b>, which exhibits high sensitivity and selectivity toward copper ions both in vitro and in vivo. <b>CS-Cu</b> was able to noninvasively monitor the changes in copper ion levels and differentiate between different mice based on copper ions in urine. Furthermore, the probe demonstrated good photoacoustic stability and exhibited no significant toxicity in the mice. These findings suggest that <b>CS-Cu</b> could be a promising tool for early detection and monitoring of Cu²⁺ levels in vivo and urine, providing a new perspective on the role of copper ions in cardiovascular disease.