title: Label-free electronic detection of bio-toxins using aligned carbon nanotubes.
abstract: A facile route for sensitive label-free detection of bio-toxins using aligned single walled carbon nanotubes is described. This approach involves patterning of a catalyst on the surface of a quartz substrate using a sub-100 μm stripe-patterned polydimethylsiloxane stamp for aligned carbon nanotube generation followed by fabrication of field effect transistor (FET). Atomic force microscopy, field emission scanning electron microscopy and Raman spectroscopy are employed to characterize the synthesized nanotubes. Unlike previous reports, the adopted approach enables direct electronic detection of bio-toxins with sensitivities comparable to ELISA. As a proof of concept, the fabricated FET responds to nM concentration levels (with a LOD of ∼2 nM) of epsilon toxin produced by Clostridium perfringens and a prominent food toxin. This facile approach could be customized to detect other classes of toxins and biomarkers upon appropriate functionalization of the aligned carbon nanotubes. Finally, we demonstrate the use of the FET-platform for detection of toxin in more complex matrices such as orange juice.
authors.affiliation: Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore 637553, Singapore. alps@ntu.edu.sg
authors.forename: Al
authors.initials: A
authors.lastname: Palaniappan
authors.forename: W H
authors.initials: WH
authors.lastname: Goh
authors.forename: D W H
authors.initials: DW
authors.lastname: Fam
authors.forename: G
authors.initials: G
authors.lastname: Rajaseger
authors.forename: C E Z
authors.initials: CE
authors.lastname: Chan
authors.forename: B J
authors.initials: BJ
authors.lastname: Hanson
authors.forename: S M
authors.initials: SM
authors.lastname: Moochhala
authors.forename: S G
authors.initials: SG
authors.lastname: Mhaisalkar
authors.forename: B
authors.initials: B
authors.lastname: Liedberg
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D013194:Staining and Labeling; D014173:Transistors, Electronic
chemical_list: D001427:Bacterial Toxins; D037742:Nanotubes, Carbon