TY - JOUR
T1 - Pretreatment of cell membranes for improved electropermeabilization- assisted dielectrophoretic impedance measurement
AU - Nakano, Michihiko
AU - Hamada, Ryo
AU - Takayama, Hiroyuki
AU - Shonishi, Yasuhiko
AU - Hisajima, Takafumi
AU - Mao, Lina
AU - Suehiro, Junya
N1 - Funding Information:
This work was partly supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (Nos. 20360184 , 21651063 , and 23760370 ).
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/10
Y1 - 2012/10
N2 - We improved our previously reported highly sensitive bacteria detection method called electropermeabilization-assisted dielectrophoretic impedance measurement (EPA-DEPIM), which counts the number of bacteria by measuring changes in impedance. EPA-DEPIM involves two processes: collection of bacteria by dielectrophoresis (DEP), followed by electropermeabilization (EP) of the cell membranes. In DEP, bacterial cells in aqueous solution are collected on microelectrodes by the dielectrophoretic force. In EP, a pulse-like rectangular wave is applied to the collected cells to disrupt their membranes. This increases the signal sensitivity because the disrupted membranes release intracellular ions that increase the change in impedance. However, the pulse-like EP wave creates a strong electric field that causes metal ions to be released from the microelectrodes, increasing the blank signal to levels comparable to that for a low-concentration Escherichia coli suspension (10 2 cells/ml). To address this problem, we demonstrated the efficacy of two types of pretreatment applied before the EP wave: chemical pretreatment by exposure to hydrogen peroxide, and physical pretreatment by a small pulse-like voltage. Both pretreatments successfully intensified the change in impedance even at a lower EP voltage.
AB - We improved our previously reported highly sensitive bacteria detection method called electropermeabilization-assisted dielectrophoretic impedance measurement (EPA-DEPIM), which counts the number of bacteria by measuring changes in impedance. EPA-DEPIM involves two processes: collection of bacteria by dielectrophoresis (DEP), followed by electropermeabilization (EP) of the cell membranes. In DEP, bacterial cells in aqueous solution are collected on microelectrodes by the dielectrophoretic force. In EP, a pulse-like rectangular wave is applied to the collected cells to disrupt their membranes. This increases the signal sensitivity because the disrupted membranes release intracellular ions that increase the change in impedance. However, the pulse-like EP wave creates a strong electric field that causes metal ions to be released from the microelectrodes, increasing the blank signal to levels comparable to that for a low-concentration Escherichia coli suspension (10 2 cells/ml). To address this problem, we demonstrated the efficacy of two types of pretreatment applied before the EP wave: chemical pretreatment by exposure to hydrogen peroxide, and physical pretreatment by a small pulse-like voltage. Both pretreatments successfully intensified the change in impedance even at a lower EP voltage.
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U2 - 10.1016/j.snb.2012.07.078
DO - 10.1016/j.snb.2012.07.078
M3 - Article
AN - SCOPUS:84867059342
VL - 173
SP - 676
EP - 681
JO - Sensors and Actuators B: Chemical
JF - Sensors and Actuators B: Chemical
SN - 0925-4005
ER -