The tissue reduction/oxidation (redox) potential is tightly regulated to maintain normal physiological processes. In contrast, it is varied under disease states, unregulated redox-active metals (Cu, Fe) will inappropriately react with O₂ to generate ROS.  To maintain redox homeostasis, various antioxidants are expressed as chemoresistance in cancer cell. Our research focuses on studying the role of in cancer cells and their pathways and mechanisms using molecular imaging probes. It can aid in early detection, differential diagnosis, therapeutic planning, and monitoring treatment response. We are developing new MRI/ optical probes to image the redox imbalances (via ROS) of tissue under cancerous conditions. We are working on transition-metal complexes as smart CAs for imaging and quantification of ROS, which functions via redox and spin crossover mechanisms for biochemical responsive magnetic resonance (MR) signal modulation.