Quantum dot (QD)-enabled electrochemical sensors are emerging as a promising technology for the early diagnosis and continuous monitoring of blood-related cancers, including leukemia and lymphoma. These nanomaterials exhibit exceptional optical features, customizable fluorescence, and a large surface-to-volume ratio, making them highly effective for the sensitive and selective identification of cancer-specific biomarkers. Their ability to detect multiple analytes simultaneously enhances diagnostic efficiency by enabling the recognition of various biomarkers or circulating tumor cells (CTCs), which is vital for early-stage detection and tracking minimal residual disease (MRD). However, potential cytotoxicity, limited biocompatibility, and regulatory hurdles must still be addressed. Ongoing research is directed toward creating safer, non-toxic QDs, refining sensor functionality, and incorporating these sensors into portable diagnostic platforms. Furthermore, integrating optical and electrochemical detection methods—alongside innovations in surface chemistry and signal amplification—is anticipated to improve both sensitivity and clinical reliability. QD-based electrochemical sensors are expected to become essential tools for early, non-invasive blood cancer diagnostics and individualized patient care as these technologies evolve.