Serological researchers accept aptamer-based biosensors as modern diagnostic instruments that outperform standard laboratory methods for cancer treatment assessment. The monitoring of cancer therapy fulfills three crucial functions, which include evaluation of treatment success, dosage adjustments, and detection of treatment resistance. Real-time cancer therapy monitoring depends on aptamer-based biosensors with their precise detection abilities. Special applications suitable for biosensor development arise from the ability of synthetic oligonucleotides known as aptamers to target specific molecules. Biosensors benefit from aptamers because of their durable binding capabilities, simple functionalization process, and high structural stability. Biosensors that use optical and electrochemical detection methods rely on aptamers to detect cancer-related biomarkers for analysis. Aptamer-based biosensors proceed by selecting and optimizing appropriate aptamers that can connect specifically with relevant biomarkers.