Biosensor-Based Detection of Cancer Biomarkers for Early Diagnosis and Treatment Monitoring

Cancer is one of the leading causes of morbidity and mortality worldwide. Early diagnosis and continuous treatment monitoring plays a critical role in improving patient survival and outcomes. Conventional diagnostic approaches such as the imaging techniques and tissue biopsy are invasive, time-consuming, and limited in their ability to detect malignancies at early or molecular stages. In recent years, biosensor technology has emerged as a promising alternative, offering rapid, sensitive, and cost-effective platforms for the detection of cancer biomarkers such as circulating tumour DNA (ctDNA), microRNAs, tumour-associated proteins, circulating tumour cells (CTCs), and exosomes. This review provides a comprehensive overview of biomarkers for cancer biomarker detection, encompassing electrochemical, optical, piezoelectric, and field-effect transistor (FET) based platforms. It provides description about the biosensor applications in major cancer types, including breast, lung, prostate, and colorectal cancers along with a comparative evaluation of key performance parameters such as sensitivity, specificity, and limit of detection. It explores the integration of biosensors with liquid biopsy techniques, microfluidic and lab-on-chip systems, and artificial intelligence for multiplexed, real-time, and point-of-care diagnostics. Along with the technological advances, challenges related to reproducibility, biological matrix interference, regulatory approval, and clinical translation continue to hinder widespread adoption. It also gives the detailed explanation of current progress, limitations, and emerging trends in biosensor development making their potential to transform early cancer diagnosis and treatment monitoring. Nanotechnology, bioengineering and clinical oncology are essential to accelerate the translation of biosensor platforms from laboratory research into routine clinical practice.