This book aims towards the introduction of nanobiosensor technology and its extensive application in the biomedical detection of clinically important analytes such as; cancer cells, anticancer drugs, proteins etc. The fabrication of the biosensor system is described using various conducting polymers and nanomaterial composites. The content of the book also describes the step by step characterization of biosensor surface using various analytical techniques such as; x-ray photon spectroscopy, quartz crystal microbalance, scanning electron microscopy, transmission electron microscopy etc. The real sample applications of the biosensor has been explained in detail using various relevant examples. This book is an attempt to explain the graduate students to start up their experiments and also help them to conceptualize ideas and its representation.