Arrays of carbon nanofibers as a platform for biosensing at the molecular level and for tissue engineering and implantation

Arrays of Carbon nanofibers (CNFs) harness the advantages of individual CNF as well the collective property of assemblies, which made them promising materials in biosensing and tissue engineering or implantation. Here, we report two studies to explore the applications of vertically aligned CNFs. First, a nanoelectrode array (NEA) based on vertically aligned CNFs embedded in SiO ₂ is used for ultrasensitive DNA detection. Oligonucleotide probes are selectively functionalized at the open ends of the CNFs and specifically hybridized with oligonucleotide targets. The guanine groups are employed as the signal moieties in the electrochemical measurements. Ru(bpy)₃ ²⁺ mediator is used to further amplify the guanine oxidation signal. The hybridization of less than ~1000 molecules of PCR amplified DNA targets are detected electrochemically by combining the CNF nanoelectrode array with the Ru(bpy)₃ ²⁺ amplification mechanism. Second, the SiO ₂ matrix was etched back to produce needle-like protruding nanoelectrode arrays to be used as cell interfacing fibers for investigating gene transfection, electrical stimulation and detection of cellular processes. Our goal is to take advantage of the nanostructure of CNFs for unconventional biomolecular studies requiring ultrahigh sensitivity, high-degree of miniaturization and selective biofunctionalization.