title: Bacterial detection using a carbon nanotube gas sensor coupled with a microheater for ammonia synthesis by aerobic oxidisation of organic components.
abstract: In this study, the authors propose a new bacteria detection method using a carbon nanotube (CNT) gas sensor and a microheater, which were coupled into a Bio-MEMS (microelectromechanical systems)-type device. Bacteria were heated by the microheater in air so that ammonia (NH(3)) gas can be generated by the oxidation reaction of organic components of bacteria. Thus generated NH(3) gas was detected by using the CNT gas sensor, which was fabricated by dielectrophoresis (DEP) and combined with the microheater to form a small chamber. Cyclic pulsed heating operation was employed so that the CNT response to elevated temperature did not mask NH(3) response. It was demonstrated that the proposed device could detect and quantify 10(7) bacteria cells (Escherichia coli). Possible application of DEP to trap and enrich target bacteria on the microheater was also discussed.
authors.affiliation: Kyushu University, Department of Electrical and Electronic Systems Engineering, Graduate School of Information Science and Electrical Engineering, Nishi-ku, Fukuoka, Japan. suehiro@ees.kyushu-u.ac.jp
authors.forename: J
authors.initials: J
authors.lastname: Suehiro
authors.forename: N
authors.initials: N
authors.lastname: Ikeda
authors.forename: A
authors.initials: A
authors.lastname: Ohtsubo
authors.forename: K
authors.initials: K
authors.lastname: Imasaka
mesh_terms: D000641:Ammonia / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D002458:Cell Fractionation / Q000295:instrumentation; D015169:Colony Count, Microbial / Q000295:instrumentation*; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D048168:Escherichia coli K12 / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D005740:Gases / Q000032:analysis / Q000737:chemistry; D006361:Heating / Q000295:instrumentation*; D008839:Microelectrodes; D008904:Miniaturization; D036103:Nanotechnology / Q000295:instrumentation; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D005740:Gases; D037742:Nanotubes, Carbon; D000641:Ammonia