Prostate cancer (PCa) and renal cell carcinoma (RCC) are among the most prevalent urological cancers. Early detection remains challenging due to the asymptomatic nature as well as heterogeneity of the cancers. The current diagnostic methods for PCa primarily rely on a blood test that measures prostate specific antigen (PSA). This test lacks both sensitivity as well as specificity, thus leading to either false positives or false-negatives. Similarly, RCC is often diagnosed incidentally during abdominal imaging for unrelated conditions. Thus, there is a need for identifying new and improved biomarkers that can make early detection easier and help in the management of these diseases. The main objective of this doctoral thesis was to identify and evaluate novel biomarkers for the detection of PCa and RCC. The focus of the study was to utilize extracellular vesicles (EVs) derived from biofluids as a non-invasive source of biomarkers to explore cancer-associated glycosylations. A novel FastEV® platform was used for the rapid isolation of EVs and combined with the nanoparticle-aided time-resolved fluorescence immunoassay (NP-TRFIA) employing europium-doped nanoparticles (Eu3+-NP) for the detection of biomarkers. Eu3+-NPs coated with a panel of antibodies or lectins were used to detect cancer-associated alterations in EVs and biofluids. The developed assays identified biomarkers such as EV tetraspanins, urinary PSMA, and serum CA19.9 and demonstrated clear differentiation between cancer and benign controls.