Graphene and its derivatives have excellent electrical, mechanical, and optical capabilities, making it the perfect foundation for sensing living things. Graphene-based nano biosensors have shown exceptional sensitivity, selectivity, and quick response times when used to detect a range of analytes, such as biomolecules, cells, and pathogens. The main uses of graphene-based nano biosensors are disease diagnosis, environmental monitoring, food safety, and drug development. It also explores prospective future strategies, such as methods for functionalizing nanomaterials, their incorporation with other nanomaterials, and the creation of wearable and implantable gadgets. Various signalling techniques, such as fluorescence, electrochemistry, surface plasmon resonance, surface-enhanced Raman scattering, etc., can be coupled with graphene-based biosensors to quantitatively detect disease-associated DNA, RNA, and protein biomarkers quantitatively. Graphene-based nano biosensors, combined with cutting-edge innovations like artificial intelligence and the Internet of Things, can completely transform industries like healthcare and environmental monitoring. Developing these biosensors with high sensitivity and low detection limits provides a new direction in medical and personal care. The later portion of the review covers the difficulties, prospective fixes, and opportunities of graphene-based biosensors.