A new method of biosensing with 1 microl of Escherichia coli suspension using atomic force microscopy.
We developed a new method for detecting bacterial cells from 1-mul samples with atomic force microscopy (AFM). The use of a parafilm surface as a sample palette was effective for reacting small amounts of samples with an AFM probe. This was due to the parafilm's hydrophobic, semitransparent, and nonadhesive surface. In this way, all processes, such as the surface functionalization of a cantilever and the adhesion of Escherichia coli cells to a cantilever, were easily completed. In addition, we succeeded in detecting cell adsorption on the same AFM cantilever by both the drive mode and the thermal mode. The resonance frequency shift caused by cell adhesion was clearly detected by the two modes for the first time. Our data indicated the potential of applying AFM nanobiosensing to extremely small amounts of samples.
Tanaka
Satoshi
S
Faculty of Engineering, Musashi Institute of Technology, 1-28-1 Tamazutsumi, Setagaya, Tokyo 158-8557, Japan.
Sugasawa
Hiroaki
H
Morii
Takashi
T
Okada
Takao
T
Abe
Masanori
M
Kato
Noriaki
N
Kuroda
Reiko
R
Nasu
Taishi
T
Nagai
Masayuki
M
Umemura
Kazuo
K
D001422:Bacterial Adhesion; D015374:Biosensing Techniques / Q000379:methods; D004926:Escherichia coli; D018625:Microscopy, Atomic Force / Q000379:methods; D036103:Nanotechnology / Q000379:methods; D018401:Sample Size; D013499:Surface Properties