Bio-sensing and analysis is an important step in the lab-on-a-chip paradigm. We develop high-throughput, multi-channel, large area graphene channel field effect transistors with enhanced sensitivity for biomolecule detection exploiting the excellent electrical and biocompatible nature of graphene. Till date biosensors using graphene have been too small as they use exfoliated graphene. Large area scaling of graphene biosensors increases sensing area and sensitivity. So we investigate the possibility of CVD graphene being an effective platform for biomolecule detection. In the present thesis, we explain how our device allows larger changes in the electrical output for enhanced sensitivity and how our novel contamination free graphene transfer technique and new approaches to device design and fabrication make our sensor devices successful. We explain underlying mechanisms behind biomolecule detection through graphene functionalization. We also present an array of biosensors, enabling detection of multiple biomolecules simultaneously. Finally, we present possible development roadmaps for our sensors.