Electrical sensing of DNA-hybridization using two-port network based on suspended carbon nanotube membrane

Abstract

An approach was presented for electrical sensing of deoxyribonucleic acid (DNA)-hybridization in solution using a two-port network based on single-walled suspended carbon nanotube (SWCNT) membrane. A single stranded probe DNA (5'-NH2-(CH2)6-CGC CGA TTG GAC AAA ACT TAA A-3') was immobilized on the SWCNT membrane. A solution with the complementary single stranded DNA (D'FITC: 5'-FITC-T TTA AGT TTT GTC CAA TCG GCG-3') in various concentrations was then dropped on the membrane. The two-port network composed of the suspended SWCNT membrane and its underneath gate were characterized by coupling with a vector network analyzer. The resonance frequency of transmission coefficient S21 was observed to be around 10 MHz. The resonance frequency shifts with DNA-hybridization, and the sensing limit was approximately 50 nM. The advantages of this approach include low-noise frequency output, solution based real time detection and capable of on-chip integration, etc.

Measuring Interfacial Adhesion of Carbon Nanotube Bundles and Electrospun Polymer Fibers

“…Single wall carbon nanotubes (SWCNTs) and electrospun polymer nanofibers (Espun) possess unique mechanical properties that allow design of freestanding structures in micro/nanoelectromechanical systems and devices, bioscaffolds for cell and tissue growth, and composite structures. The microscopic architecture offers distinct advantages over conventional patterning in many ways (e.g., circuits on planar electronic substrates), and facilitates exploration of the complex interplay between electronic, mechanical, thermal, and even biological phenomena. − The mechanical properties of fibers and their adhesion at similar (e.g., CNT–CNT) and dissimilar (e.g., CNT–Espun) interfaces are critical parameters determining the overall mechanical integrity and performance, long-term reliability, and feasibility of constructing overhanging microstructures, etc. A fiber network comprises ultrahigh strength but weak interfiber adhesion falls apart and the structure crumbles upon small external load.…”