CHAPTER 13 Carbon-based nanomaterials as novel nanosensors Shreya Sharma a , Shashank Shekhar a , Sanjeev Gautam a , Bhasha Sharma a , Amit Kumar b , Purnima Jain a a Netaji Subhas University of Technology, Delhi, India b Dyal Singh College, University of Delhi, Delhi, India 13.1 Introduction Nanotechnology is an emerging field that focuses on creation, manipulation, exploitation, and engineering of atoms, molecules, and supramolecular structures, i.e., matter and particle structures on the nanometer scale. These nanomaterials range from 1 to 100 nm in size and are known for remarkably changing their characteristics in the nanorange with outstanding properties, thus offering the possibility of implementation in newer domains with improved performance. A sensor is a device that measures and detects changes in a somatic stimulus that translate into a human-readable display at the sensor location or an evaluable signal that can be recorded for further processing (e.g., electrical, optical, or mechanical). High sensitivity and authenticity, quicker recovery, faster response, reduced size, minimal cost, simple operations, and in-situ analysis are the major attractions of sensor systems. However, most current sensors come with pretreatment needs, difficult operation, slow response, and no ideal limits of detection, sensitivity to sensory stimuli, and/or selectivity, all of which demands an alternative approach. Nanosensors are nanosized sensing tools. Their expanding role in physical and chemical sensing is wide-ranging, including biochemical diagnosis in tissues and quantification of nanoscale particles and surroundings, and has led scientists to perform more incremental research in this sector. An overview of a variety of sensors in use is displayed in Fig. 13.1. Carbon-based materials are among the most researched and currently used materials in the nanotechnology field, because of their impressive characteristics. Carbon materials present innumerable benefits over other conventionally used materials. Their inherent electrical characteristics, sensitive to alterations in the chemical surroundings, single them out as the most Nanofabrication for Smart Nanosensor Applications. https://doi.org/10.1016/B978-0-12-820702-4.00014-3 # 2020 Elsevier Inc. All rights reserved. 323