The objective of this award is to develop and test a novel nanofluidic-nanoelectronic device with high specificity and sensitivity for biological sensing applications. To exploit the recently discovered nanofluidic advantages of carbon nanotube (CNT) nanochannel, nanofluidic devices based on high quality horizontally aligned single-walled CNT (SWCNT) arrays will first be fabricated. Then, the electrokinetic motion of analytes passing through the interior of CNT arrays will be characterized and controlled. Subsequently, practical approaches will be developed in these CNT nanofluidic devices to utilize several CNT based electrical sensing methods, including field effect transistor (FET), electrochemical sensing and capacitive charge sensing methods. Fundamental understandings of these sensing methods when they are incorporated into nanofluidic devices will be developed and different sensing methods will be combined together to achieve multimode sensing. Finally, the biosensor performance will be evaluated through the detection of secreted small molecules from individual living cells in real time. If successful, this highly interdisciplinary research will develop new ways to integrate nanofluidics and nanoelectronics into one device. The knowledge and methods obtained from this project can be applied to other metallic or semiconducting nanotubes and nanopores. This project will lead to a new type of all-electrical biosensor, which will be ultrasensitive, highly selective, portable, cheap, requiring a low sample and power consumption. A new class of biosensor for single living cell sensing will be developed. The developed biosensor is also potentially applicable to a wide variety of areas: clinic diagnostics, environment protection and preservation, health improvement, national defense and bioterrorism prevention.