Hypoxia is a state of reduced oxygen in tissues characteristic of most solid tumors and hematologic malignancies often manifested by overexpression of oxidoreductases. The project focuses on checking the affinity of hypoxia-activated prodrugs (HAPs) and fluorescent sensors for oxidoreductases with nitroreductase activity. The reduction of prodrugs and sensors, catalyzed by these enzymes, enhances cytotoxic properties and fluorescent intensity, respectively. Molecular docking and biophysical methods will be applied to determine the binding affinity and propose changes in the substrate structure that can increase this affinity. Better sensor efficiency can be achieved by selective delivery to target sites, among others, by conjugating them to proteins. The impact of such conjugation on the sensor affinity toward selected oxidoreductases will also be assessed. The results obtained may contribute to developing effective and selective anticancer therapies and new diagnostic methods.