2003 Fiscal Year Final Research Report Summary
Selective bacteria detection using dielectrophoretic impedance measurement combined with antigen-antibody reaction
| Project/Area Number |
14550421
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Measurement engineering
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| Research Institution | Kyushu University |
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Principal Investigator |
SUEHIRO Junya Kyushu University, Faculty of Information Science and Electrical Engineering, Associate Professor, システム情報科学研究院, 助教授 (70206382)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Iwao Department of Health Sciences, School of Medicine, Research Associate, 医学部保健学科, 助手 (50038931)
IMASAKA Kiminobu Kyushu University, Faculty of Information Science and Electrical Engineering, Research Associate, システム情報科学研究院, 助手 (40264072)
HARA Masanori Kyushu University, Faculty of Information Science and Electrical Engineering, Professor, システム情報科学研究院, 教授 (30039127)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Dielectrophoresis / Impedance / Antigen-antibody reaction / Bacteria inspection / Electropermeabilization / Carbon nanotube / Electrochemical reaction / Gas sensor |
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| Research Abstract |
(1)Selective DEPIM (dielectrophoretic impedance measurement) using antigen-antibody reaction
-Two kinds of combinations of DEPIM with immunoassay are tested. In one method, agglutination of bacteria is employed to increase dielectrophoretic force. The other method utilizes antibody molecules immobilized onto the microelectrode surface.
-Both methods can leave peculiar bacteria on the electrode surface after preliminary dielectrophoretic enrichment. Agglutinated or immobilized bacteria can be electrically detected by residual increase of the electrode conductance.
(2)Dielectrophoretic filter for recovery and enrichment of bacteria
-The bacteria suspension was enriched by 30 times in one hour using a multi-segment DEP filter.
-The DEP filter enrichment was successfully combined with DEPIM for bacteria detection at lower density as a pre-enrichment procedure.
(3)High sensitive DEPIM using electropermeabilization
-By applying high ac electric field to the trapped bacteria, abrupt conductance increase, which is possibly caused by electropermeabilization, is observed.
-For yeast cells, the lower limit of DEPIM sensitivity is improved from 10^4 to 10^2 CFU/ml for 15 min diagnosis time.
(4)Dielectrophoretic manipulation of carbon nanotubes and gas sensor application
-Carbon nanotubes (CNTs) were trapped and enriched in an microelectrode gap under the action of a positive DEP force. During the DEP trapping, the electrode impedance varied as the number of CNTs increased.
-The microelectrode retaining the CNTs could detect ammonia gas below 10 ppm concentration.
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