Nanotube Crossbar Array via Microcontact Printing for Biomolecule Detection

Abstract

AbstractThe paper describes the fabrication and characterization of an ionic junction nanodevice as a biosensor using surfactant coated single walled carbon nanotubes (SWCNT's) via microcontact printing and its application in detecting standard protein biomolecules ( biotin-avidin). Intrinsic semiconducting SWCNT's are doped with anionic and cationic surfactant molecules respectively. Using double patterning process, these ionically doped anionic and cationic semiconducting SWCNT's are alternatively symmetrically patterned in a parallel array to form crossbar junctions onto base microelectrode arrays using flexible polymeric poly-dimethylsiloxane (PDMS) stamps. Parallel alignment of SWCNT's is achieved, due to transfer of the inked SWCNT's from the PDMS relief structure onto the microelectrode array. Base microcontacts on the microelectrode array serve as a platform for measuring electrical characteristics that get modulated due to the biomolecule binding. Functionality of the nanodevice is demonstrated by measuring impedance changes due to biomolecule binding. The modulation of the electrical behavior indicates the existence of potential for using ionically doped nanomaterial systems in fabricating functional building blocks for biosensors.